chemistry question bank

Question Bank Based on Board Papers
Prepared By Mrs. S.Srivastava
(The Solid States)

4 marks

SAMPLE PAPER- 1 (OLD)
Q9) Equal no. of cation & anion missing in the diagram is given.
(i)
What are these types of vacancy defects called?
(ii)
How is the density of crystal affected by these defects?
(iii) Name one ionic compound which can show this type of defect in crystalline state.
(iv)
How is the stoichiometry of compound affected?
Q10) Analysis shows that M.O. has E.F.M 0.96 O 1.00 Calculate % M 2+ & M 3+ ions in
the crystal
Q10) In an ionic compound N- form cubic close type packing while the cation M+
ions occupy one third of the tetrahedral voids. Deduce the formula of
compound & the C.N. of M+ ions.
SAMPLE PAPER- 2 (OLD)
Q5) A compound contains 2 types of atoms X & Y . It crystallizes in a cubic lattice
with atom X at the corner & Y at body centres. What is the simplest possible
formula of compound.
Q19) An element X with an at.mass 60 g/mol has density 6.23 g/cm3 If the edge
length of cubic unit cell is 400pm.Identify the type of cubic unit cell.
Calculate the radius of an atom of this element.
SAMPLE PAPER- 3 (OLD)
Q1) Name the type of point defect that occurs in a crystal of ZnS.
Q4) How many octahedral voids are there in one mole of a compound having
cubic close packed Structure?

Q9) An element crystallizes in BCC structure.If the edge length of the cell is
1.469 x 10 -10 m. & density is 19.3 g/cm3. Calculate the at. Mass of this element.
Also calculate the radius of an atom of this element.
2008 D
Q1)What is the C.N. of each type of ions in a rock salt type crystal structure?
Q19) what is a semiconductor? Describe the two main types of semiconductors
& explain mechanism for their conduction.
Q1) What is the total no. of atoms per unit cell in a FCC structure?
Q1) What is the total no. of atoms per unit cell in a FCC structure?
Q1) What type of substance exhibits antiferromagnetism?
Q19) Reasons: (i) Frenkel defects are not found in alkali metal halides.
(ii)Schottky defects lower the density of related solids.
(iii) Impurity doped Si is a semiconductor.
Q19) Explain (i) Ferromagnetism (ii)Paramagnetism (iii) Ferrimagnetism.
2008 AI
Q1) What is the total no. of atoms per unit cell in a FCC structure?
Q19) Ag crystallizes in FCC lattice. The edge length of its unit cell is 4.077 x 10 -8
cm. & its density is 10.5 g/cm3 Calculate the at. Mass of Ag.
2008 F
Q1) What type of alignment in crystals make them ferromagnetic
Q19) Reasons: (i) Frenkel defects are not found in alkali metal halides.


(ii)Schottky defects lower the density of related solids.
(iii) Impurity doped Si is a semiconductor.
Q19) Explain (i) F-centre (ii)Paramagnetism (iii) Frenkel defect
2008 D COMPTT
Q1) Name an element with which Si should be doped to give n- type
semiconductor.
Q19) Explain (i) F-centre (ii) Schottky defect (iii) Ferromagnetism

2008 AI COMPTT
Q1) What are F- centres?
Q19)Reason: (i) Fe3O4 is ferromagnetic at room temperature but becomes
paramagnetic at 850K.
(ii) ZnO on heating becomes yellow.
(iii) Frenkel defect does not change the density of AgCl crystals
Q19) With the help of suitable diagram, on the basis of Band theory,explain the
difference between (a)A conductor & an insulator (b) A conductor &
semiconductor.
Q8) Why is glass considered a supercooled liquid
Q4) What is the two dimensional coordination no. of a sphere in square close
packing?
2009 AI
Q1) How do metallic & ionic substance differ in conducting electricity?
Q20) Ag crystallizes with FCC unit cells. Each side of the unit cell has a length of
409 pm what is the radius of an atom of Ag?
Q1) Which point defect of its crystals decreases the density of a solid?
Q19) Fe has a BCC unit cell with a cell edge of 286.65 pm. The density of Fe is
7.87 g/cm3. Calculate Avogadro’s no. (at. Mass Fe=56 g/mol)
Q1) What is the total no. of atoms per unit cell in a FCC structure?
2009 D
Q1) Which point defect in crystal does not alter the density of the relevant solid?
Q1) Which point defect in crystal alter the density of solid?
Q1) Which point defect in crystal increases the density of solid?
2009 F
Q1) What is the no. of atoms in a BCC unit cell of a crystal
2009 D COMPTT
Q13) How are the following properties of crystals affected by Schottky & Frenkel
defects?(i) density (ii) electrical conductivity
Q13) (a) In reference to crystal structure, explain the meaning of C.N.(b) What is

the no. of atoms in a unit cell of FCC & BCC structure
Q14) Cu crystallizes into a FCC lattice with edge length 3.61 x 10 -8 cm. Calculate
the density of Cu? (Cu = 63.5 g/mol)
2010 AI
Q1) What type of interaction hold the molecules together in a polar molecular
solid?
Q19 ) The density of Cu metal is 8.95 g / cm3 If the radius of Cu atom be 127.8pm
Is the unit cell simple cubic , BCC or FCC?
( Cu = 63.54 g /mol , NA = 6.02 x 10 23 mol-1)
Q1) What type of semiconductor is obtained when Si is doped with As?
Q19) Ag crystallizes in FCC cubic unit cell. Each side of the unit cell has a length
of 409 pm. What is the radius of Ag atom.
Q1)Write distinguishing feature of metallic solids.
Q19) Ag crystallizes in FCC cubic unit cell. If the edge length of unit cell is


4.07 x 10-8 cm. and density 10.5 g/cm3. Calculate the atomic mass of Ag
(NA = 6.02 x 10 23 mol-1)
2010 D
Q1)Write distinguishing feature of metallic solids from an ionic solid.
Q19)In one unit cell of CaF2 there are 4Ca2+ and 8 F- ions.Ca2+ are arranged in
FCC lattice.The F- ions fill all tetrahedral holes in the FCC lattice of Ca2+
ions,The edge of the unit cell is 5.46 x 10 -8 cm in length,the density of solid
is 3.18 g/cm3.Calculate Avogadro’s no. (M.M. of CaF2 =78.08 g/mol)
Q1) Which point defect in crystal of solid does not change the density of solid
Q1) Which point defect in crystal of solid decreases the density of solid
2010 F
Q1) What is the no. of atoms in a unit cell of a simple cubic crystal?
Q19) Fe has a BCC unit cell with a cell edge of 286.65 pm. The density of Fe is
7.87 g/cm3. Calculate Avogadro’s no. (at. Mass Fe=56 g/mol)

NEW SAMPLE PAPER I
Q1) Why LiCl acquires pink colour when heated in Li vapours.
Q17) Sodium crystallizes in BCC unit cell. Calculate the approximate no. of unit
cells in 9.2 g of sodium (Na = 23)
Q18) What is a semiconductor? Describe the two main types of semiconductors.
NEW SAMPLE PAPER II
Q10) KF has CCP structure. Calculate the radius of unit cell if the side of the
cube or edge length is 400 pm.How many F- ions and octahedral voids are
there in this unit cell.
Q11) Give reasons:
(a) Why is Frenkel defect found in AgCl?
(b) What is the difference between P doped and Ga doped semiconductors.
NEW SAMPLE PAPER III
Q9) Au )at.mass 197 u , at, radius= 0.144 nm) crystallizes in a FCC unit cell.
Determine the density of Au.(NA = 6.022 x 10 23 mol -1)
Q10) Classify each as being either p-type or n-type semiconductor. Give reason.
(a)Si doped with In
(b) Si doped with P
2011 AI
Q9) Explain how you can determine the at.mass of an unknown metal if you know
its mass, density and the dimensions of unit cell of its crystal.
Q10) Calculate the packing efficiency of a metal crystal for a simple cubic
lattice.
Q9)Define the following terms in relation to crystalline solids
(a) Unit cell (b) co-ordination no.
Give one example in each case.
2011 D
Q1) Crystalline solids are anisotropic in nature. What does this statement mean?
Q19) Ag crystallizes in FCC unit cell. Each side of this unit cell has a length of
400pm. Calculate the radius of Ag atom.

Q1) Which stoichiometric defect in crystal increases density of solid?
Q19) The density of lead is 11.35 g/cm3 and the metal crystallizes with FCC unit
cell. Estimate the radius of lead atom. (Pb = 207 g/mol)
2011 F
Q1) What is meant by an intrinsic semi conductors?
Q19) Al crystallizes in CCP. Radius of atom in metal is 125 pm.
(a) What is the length of side of unit cell?


(b) How many unit cells are there in 1cm3 of Al
Q1) How many atoms are there in one unit cell of BCC crystal?
Q19) Ag crystallizes in FCC unit cell. Each side of this unit cell has a length of
409 pm. Calculate the radius of Ag atom.
2010 D COMPTT
Q13) How are the following properties of crystals affected by Schottky and
Frenkel defects (i) density (ii) Electrical conductivity.
Q13) (a) In reference to crystal structure , explain the meaning of coordination
number.
(b ) What is the number of atoms in a unit cell of
(i)
a FCC structure (ii) a BCC structure
Q14) Copper crystallizes into an FCC lattice with edge length 3.61 x 10 -8 cm.
Calculate the density of copper (Cu= 63.5 g/mol ,NA = 6.022 x 1023 /mol)
2010 AI COMPTT
Q1) Give an example of an ionic compound which shows Frenkel defect.
Q19) Copper crystallizes into an FCC lattice and has a density of 8.930g/cm3 at
293 K . Calculate the radius of copper atom.
(Cu= 63.5 g/mol , NA = 6.022 x 1023 /mol)
2012 AI
Q1) how may the conductivity of an intrinsic semiconductor be increased?

Q19) copper crystallizes with FCC unit cell. if the radius of Cu atom is
127.8 pm, calculate the density of Cu metal. (at.mass of Cu = 63.55 u
and NA = 6.02 x 10 23 /mol)
Q19)iron has BCC unit cell with cell dimension of 286.65 pm. Density of iron is
7.87 g/cm3.use this information to calculate Avogadro’s number.
(at.mass of Fe = 56.0u)
Q1) which stoichiometric defect increases the density of a solid?
Q1) what are n-type semiconductors?
2012 D
Q1) What is meant by doping?
Q19) Tungsten crystallizes in body centred cubic unit cell.If the edge of the unit
cell is 316.5 pm.What is the radius of tungsten atom?
Q19) Iron has a body centred cubic unit cell with a cell dimension of 286.65 pm
The density of iron is 7.874 g/cm3 Use this information to Calculate
Avogadro’s number.(at. Mass of Fe = 55.845 u)
Q1)Write a point of differences between a metallic solid and an ionic solid other
than metallic luster.
2012F
Q1)What is meant by the term ‘forbidden zone’ in reference to band theory of
solids?
Q19) Iron has a body centred cubic unit cell with a cell dimension of 286.65 pm
The density of iron is 7.874 g/cm3 Use this information to Calculate
Avogadro’s number.(at. Mass of Fe = 55.845 u)
Q19) Silver crystallizes in FCC unit cell.If the radius of silver atom is 145 pm,
what is the length of each side of unit cell?
Q1)Write a point of differences between a metallic solid and an ionic solid other
than metallic luster.
Q1) Define paramagnetism with an example.

2013 AI
Q9) account for the following:
(i)
schottky defects lower the density related solids.
(ii)
Conductivity of silicon increases on doping it with phosphorus
Q10) aluminium crystallizes in a fcc structure .atomic radius of the metal is 125
pm. What is the length of the side of the unit cell of the metal?
Q9) (a) why does presence of excess of lithium makes LiCl crystals pink?
(b ) a solid with cubic crystal is made of two elements P and Q. atoms of Q are at the corners of
the cube and P at the body centre . what is the formula of the compound.
Q13) (a) what change occurswhen AgCl is doped with CdCl2?
( b ) what type of semiconductor is produced when silicn is doped with boron
Solid state
FORMULAE :
LIMITING RADIUS RATIO r+/ rFOR CsCl STRUCTURE
r+ (CATION RADII) =0.732
(C.N.8)
r- (ANION RADII)
FOR NaCl STRUCTURE
r+ (CATION RADII) =0.414-0.732
(C.N.6)
r- (ANION RADII)
FOR ZnS STRUCTURE
r+ (CATION RADII) =0.225 – 0.414 (C.N.4)
r- (ANION RADII)
FORMULA OF ACOMPOUND:
NO. OF OCTAHEDRAL VOID=N
NO. OF TETRAHEDRAL VOID = 2N
RELATIONSHIP BETWEEN RADIUS OF THE SPHERE AND UNIT CELL EDGE

LENGTH
SIMPLE a =2r
F.C.C. a = 4 / √2 r
B.C.C. a = 4 /√3 r
DENSITY OF THE UNIT CELL
d = z M / a3 NA = no. of atoms per unit cell x molar mass
(cell edge length)3 x Avogadro’s No.
Imp.
Points
to
be
noted:
AS DENSITY OF ELEMENT IS GIVEN IN g/cm 3 , THE EDGE LENGTH IS TO BE
CHANGED
IN
cm.
IF VALUE OF a IS GIVEN IN pm THEN IT SHOULD BE MULTIPLIED BY10 -30
FOR NaCl STRUCTURE CELL LENGTH = 2 X DISTANCE BETWEEN Na + AND Cl- ION
IN
SOME
NUMERICALS
d

=

wt.
OF
ELEMENT
X
NO.

OF ATOMS
PER
UNIT
CELL
3
(CELL EDGELENGTH) X NO. OF ATOMS PRESENT IN ELEMENT
M IS AT. MASS IN CASE OF ELEMENTS AND MOLAR MASS IN CASE OF IONIC
MOLECULE
LIKE
NaCl
VALUE OF z
SIMPLE CUBE = 1
B.C.C. = 2
F.C.C. = 4
CsCl = 1 , NaCl = 4 ,ZnS = 4
Question Bank
(Solutions)

5 marks

SAMPLE PAPER- 1 (OLD)
Q11) Diagram of R.O. given. (i)Name the process occurring in the above plant.
(ii) To which container does the net flow of solvent take place?
(iii) Name one SPM which can be used in this plant.
(i)
Give the practical use of the plant.
Q19) Heptane & Octane form an ideal solution at 373 K. The V.P. of the pure


liquid at this temperature is 105.2 KPa & 46.8 KPa resp. if the solution

contains 25g of heptanes & 28.5 g of octane. Calculate
(i)
V.P. exerted by heptanes (ii) V.P. exerted by solution
(iii)mole fraction of octane in theV.P.
SAMPLE PAPER- 2 (OLD)
Q6) What is van’t Hoff factor for a compound which undergoes tetramerization in
an organic compound ?
Q9)Ethylene glycol (M.M. = 62 g/mol) is an antifreeze. Calculate F.P. of solution
containing 12.4 g of substance in 100 g of water. Would it be advisable to
keep the substance in the car radiator during summer
(kf for water = 1.86 KKg/mol , Kb for water= 0.512 KKg/mol)
Q18) Reason: (a) At higher altitude people suffer from a disease called anoxia. In
this disease they become weak & can’t think clearly.
(b) When HgI2 is added to KI , the F.P. is raised?
SAMPLE PAPER- 3 (OLD)
Q28) (a) Derive relationship between relative lowering of V.P. & mole fraction of
the volatile liquid
(b) (i) Benzoic acid completely dimerises in benzene. What will be the V.P. of a solution
containing 61 g of benzoic acid per 500 g benzene when the V.P. of pure benzene at the
temp. of experiment is 66.6 Torr.
(ii)
What would have been the V.P. in the absence of dimerization.
(iii) Derive a relationship between mole fraction & V.P. of a component of an ideal
solution in the liquid phase & vapour phase.
Q28) (a) Which aqueous solution has higher concentration 1M or 1 molal solution
of the same mole? Give reason.
(b) 0.5 g KCl was dissolved in 100 g water & the solution originally at 20 0C, froze at -0.24 0C
Calculate % ionization of salt (Kf= 1.86 KKg /mol)
2008 D
Q11) State Henry’s law correlating the pressure of a gas & its solubility in a

solvent & mention two applications for the law.
Q20) Calculate the temp. at which a solution containing 54 g of glucose
(C6H12O6) in 250 g of water will freeze (Kf for water =1.86 KKg/mol)
Q9) State Raoult’s law for solution of volatile liquids taking suitable
examples. Explain the meaning of positive & negative deviations from
Raoult’law.
Q9) Define the term O.P. Describe how the mol.mass of a substance can be
determined by a method based on measurement of O.P.
2008 AI
Q20) A solution containing 8 g. of substance in 100 g of diethyl ether boils at
36.86 0C whereas pure ether boils at 35.6 0C Determine the mol.mass of
solute.( Kb for ether = 2.02 KKg/mol)
Q20) Calculate the temperature at which a solution containing 54 g of glucose
(C6H12O6) in 250 g of water will freeze.(Kf for water = 1.86 KKg/mol)
2008 F
Q3) (a) State how the V.P, of a solvent is affected when a non volatile is dissolved
in it .
( b )A 5% solution ( by mass ) of cane sugar in water has a F.P. 271K
Calculate the F.P. of 5% (by mass) solution of glucose in water.
(F.P. of water is 273.15K,M.M.of sugar = 342g/mol & M.M. of glucose = 180 g/mol)
Q4) (a) If density of water of a lake is 1.25 g/mol & 1 kg of lake water contains
92g of Na+ ions. Calculate the molarity of Na+ ions in this lake water.
(b)Calculate the mass of a non volatile solute ( mol mass 40 g/mol) which
should be dissolved in 114 g of octane to reduce its V.P. to 80 %


(M.M. of octane = 114 g /mol )
2008 D COMPTT
Q28) (a) The depression of F.P. of water observed for the same molar concn of
acetic acid, trichloroacetic acid & triflouroacetic acid increases in the

order as stated above .Explain .
( b )Calculate the depression in F.P. of water when 20 g of
CH3CH2CH(Cl) COOH is added to 500 g of water.
(Ka =1.4 x10-3, Kf= 1.86KKg /mol)
Q28) (a) State Henry’s law & mention its two important applications.
(b) Henry’s law constant for CO 2 dissolving in water is 1.67 x 10 8 Pa at 298 K. Calculate
the quantity of CO2 in 1L of soda water when packed under 2.5 atm CO 2 pressure at
298 K.
2008 AI COMPTT
Q9) What is meant by negative deviation from Raoult’s law? Draw diagram to
illustrate the relationship between V.P. & mole fraction of components in a
solution to represent negative deviation.
Q20) The b.p. elevation of 0.3g of acetic acid in 100g benzene is 0.0633K.
Calculate the molar mass of acetic acid from this data.What conclusion can
you draw about the molecular state of the solute in solution?
(Kb for benzene = 2.53KKg/mol)
Q18) Distinguish between the terms molality & molarity.Under what conditions
are the molarity & molality of a solution nearly the same?
Q26) The F.P. of a solution containing 0.2 g of acetic acid in 20 g of benzene is
lowered by 0.450 Calculate (i) the mol.mass of acetic acid from this data.
(ii) van’t Hoff factor
(Kf benzene = 5.12 K Kg/mol) What conclusion can you draw from the value of
van’t Hoff factor obtained.
Q13) What are non ideal solutions? Give one example.Explain as to why non ideal
solution deviate from Raoult’s law.
Q21) Calculate the amount of KCl which must be added to 100 g of water so that
water freezes at –20C Assume that KCl undergoes complete dissociation.
(Kf = 1.86KKg/mol , K=39,Cl=35.5)
2009 AI
Q28) (a) Define (i) mole fraction (ii) van’t Hoff factor

(b)100mg of a protein is dissolved in enough water to make 10 ml of a solution.If this
solution has an O.P. of 13.3 mm Hg at 25 0CWhat is the molar mass of protein? (R= 0.0821
Latm/mol/K & 760 mm Hg=1atm)
Q28) (a) What is meant by (i) Colligative property (ii) molality of solution
(b)What concentration of N2 should be present in a glass of water at room temp.?Assume
temp. of 250C , a total pressure of 1 atm & mole fraction of N2 in air of 0.78
(KH for N2 = 8.42 x 10 –7 M/mmHg)
2009 D
Q13) Differentiate between molality & molarity of solution.What is the effect of
change in temp. of a solution on its molality or molarity?
Q19) Calculate F.P. depression expected for 0.0711 m aq.solution of Na2SO4. If
this solution actually freezes at –0.320C What would be the value of van’t
Hoff factor (Kf for water = 1.86KKg/mol)
2009 F
Q2) What is reverse osmosis?
2009 D COMPTT
Q5) Define the term Osmotic Pressure.
Q6) State the main advantage of molality over molarity as the unit of


Concentration
Q27) Calculate the amount of NaCl which must be added to 1 kg of water is
depressed by 3K. ( Kf = 1.86KKg/mol, Na=23,Cl=35.5)
Q5) State Raoult’s law for solution of volatile liquid.
Q6) Define ideal solution
Q19) A solution of urea in water has a b.p. 373.128K Calculate the F.P. of the
same solution. (Kf = 1.86Km-1 , Kb=0.52Km-1)
Q23) 0.1 mole of acetic acid was dissolved in 1 kg of benzene. Depression in F.P.
of benzene was determined to be 0.256K. What is the state of solution?
(Kf for benzene = 5.12K/m)

2010 AI
Q9) Define the term osmosis and osmotic pressure.What is the advantage of
using O.P. as compared to other colligative properties for the determination
of molar masses of solute in solution.
Q20) What mass of NaCl ( M.M. = 58.5 g/mol) must be dissolved in 65 g of water
to lower the F.P. by 7.5 0C ? The F.P. depression constant Kf for water is
1.86 Kkg/mol. Assume that van’t Hoff factor for NaCl is 1.87.
Q20) What mass of ethylene glycol (M.M = 62 g/mol) must be added to 5.5 kg of
water to lower the F.P. of water from 0 0 C to – 10 0C ?
(Kf for water = 1.86 Kkg/mol)
Q20) 15 g of an unknown molecular substance was dissolved in 450 g of water .
The resulting solution freezes at – 0.340C What is the molar mass of
substance?
(Kf for water = 1.86 Kkg/mol)
Q2) Differentiate between molarity and molality of a solution.
2010 D
Q9)Non ideal solution exhibits either +ve or –ve deviation from Raoult’s law.What
are these deviations and why they are caused?Explain with one example of
each.
Q20) A solution prepared by dissolving 1.25 g of oil of winter green in 99 g
benzene has a b.p. of 80.31 0C.Determine the molar mass of this
compound.
( b.p. of pure benzene = 80.10 0C. and Kb for benzene = 2.530C kg/mol.)
Q20) A solution of glycerol(M.M. = 92 g/mol) in water was prepared by dissolving
some glycerol in 500 g of water.This solution has a b.p. of 100.42 0C What
mass of glycerol was dissolved to make the solution.
(Kb for water = 0.512 Kkg/mol)
2010 F
All questions repeated
NEW SAMPLE PAPER I

Q28) (a)Menthol is a crystalline substance with peppermint taste. A 6.2%
solutionOf menthol in cyclohexane freezes at-1.950 C. Determine the
formula mass of menthol.The F.P. and molal depression constant of
cyclohexane are 6.5 0C and 20.2 K m-1 respectively,
(b) State Henry’law and mention its two important applications.
( c ) Which of the following has higher b.p. and why?
0.1M NaCl or 0.1M glucose
Q28)(a) Define azeotropes and explain briefly minimum boiling azeotrope by
taking suitable example.
( b ) The V.P. of pure liquids A and B are 450 mm and 700 mm of Hg
respectively at 350 K.Calculate the composition of liquid mixture if
total V.P, is 600 mmHg.Also find th composition of the mixture in
vapour phase.


NEW SAMPLE PAPER II
Q13) State Raoult’s law for a solution containing volatile liquids.Explain with
suitable example the concept of max. boiling azeotrope.
Q24)On dissolving 19.5 g of CH2FCOOH in 500 g of water a depression of 1 0C in
F.P. of water is observed. Calculate the van’t Hoff factor and dissociation
constant of flouro acetic acid, Given Kf = 1.86Kkg/mol
NEW SAMPLE PAPER III
Q1) A and B liquids on mixing produce a warm solution. Which type of deviation
from Raoult’s law is there?
Q11) Determine the molarity of an antifreeze solution containing 250 g water
mixed with 222 g ethylene glycol. The density of the solution is 1.07 g/ml
Q12)An aqueous solution containing urea was found to haveb.p. more than the
normal b.p. of water(313.13K)When the same solution was cooled it was
found that its F.P, is les than the normal b.p. of water(273.13K)
Explain these observations

2011 AI
Q11)State the following.
(a) Raoult’s law in its general formin reference to solutions
(b) Henry’s law about partial pressure of a gas in a mixture
Q19) A solution prepared by dissolving 8.95 mg of a gene fragment in 35 ml of
Water has an O.P. of 0.335 Torr at 25 0 V Assuming that the gene fragment
is a non electrolyte,calculate its molar mass.
Q19)What mass of NaCl must be dissolved in 65 g of water to lower the F.P. of
water by7.5 0C?TheKf for water is1.86 0C/m. Assume van’t Hoff factor for
NaCl is1.87(M.M. of NaCl is 1.87(M.M. of NaCl=58.5 g)
Q2)What is reverse osmosis?
Q3)Differentiate between molarity and molality values for solution.What is the
effect of change in temperature on molarity and molality values?
2011 D
Q28) (a) Differentiate between molarity and molality for a solution. How does a
change in temperature influence their values.
(b ) Calculate F.P. of aq. solution containing 10.5 g of MgBr2 in 200g of
water (MM of MgBr2 = 184g) (Kf for water = 1.86 Kkg/mol)
Q28) (a) Define osmosis and osmotic pressure. Is the O.P.of a solution a
colligative property? Explain.
(b )Calculate the b.p. of a solution prepared by adding 15 g of NaCl to 250 g
of water.(Kf for water = 0.512 Kkg/mol , M.M. of NaCl = 58.44g)
Q28) (a) repeated
(b ) What would be the M.M. of a compound if 6.21 g of it dissolved in 24 g of
chloroform a solution that has a b.p. of 68.04 0C. The b.p. of pure
chloroform is 61.7 0C . ( Kb for chloroform = 3.63 0C/m)
2011 F
Q2) State Henry’s law about partial pressure of a gas in a mixture.
Q9) Differentiate between molarity and molality for a solution. Explain how
molarity value of a solution can be converted into its molality.

Q10) A 0.561 m solution of an unknown electrolyte depresses the F.P. of water
by 2.93 0C. What is van’t Hoff factor for this electrolyte. (Kf = 1.86 0C/kg/mol)
2010 D COMPTT
Q5) Define the term Osmotic Pressure.
Q6) State the main advantage of molality over molarity as the unit of
concentration.
Q27) Calculate the amount of NaCl which must be added to one kg of water so
that the F.P. of water is depressed by 3K.
(Kf = 1.86 Kkg /mol,Na =23, Cl=35.5)


Q4) State Raoult’s law for a solution of volatile liquids
Q19) A solution of urea in water has a b.p. of 373.128K.Calculate the F.P. of the
Same solution.(Kf for water = 1.86K/m , Kb = 0.52 K/m)
Q1) Define an ideal solution.
Q23) 0.1 mole of acetic acid was dissolved in 1 kg of benzene. Depression in
F.P. of benzene was determined to be 0.256 K . What conclusion can you
draw about the state of the solute in solution (Kf for benzene = 5.12 K/m)
2010 AI COMPTT
Q2) Define the term, mole fraction.
Q9) State Henry’s law and mention its two important applications.
Q10) Calculate the mass of ascorbic acid (C6H8O6) to be dissolved in 75 g of
acetic acid to lower its melting point by 1.5 0C
(Kf for acetic acid = 3.9 Kkg /mol)
Q17) Find the b.p. of a solution containing 0.520 g of glucose (C6H12O6)
dissolved in 80.2 g of water.(Kb for water =0.52 K/m)
Q18)Define the term Molarity of a solution. State one disadvantage in using the
molarity as the unit of concentration.
Q13) Find the f.p. of a solution containing 0.520 g of glucose (C6H12O6)
dissolved in 80.2 g of water.(Kf for water = 1.86 K/m)

2012 AI
Q28) (a) define the following terms:
(i)
Mole fraction
(ii)
Ideal solution
(b) 15 g of an unknown molecular material is dissolved in 450 g of water.
the resulting solution freezes at -0.34 0 C. what is the molar mass of the material?(Kf for
water = 1.86 Kkg /mol)
Q28) (a) explain the following:
(i)
Henry’s law about dissolution of gases in a liquid
(ii)
Boiling point elevation constant for a solvent
(b)a solution of glycerol (C3H8O3) in water was prepared by dissolving some
glycerol in 500 g of water. this solution has b.p.of 100.420C.what mass of
glycerol was dissolved to make this solution?
(Kb for water = 0.512 K kg /mol. )
2012D
Q9)A 1 molal aqueous solution of trichloroacetic acid is heated to its b.p. The
solution has the b.p. of 100.18 0C.Determine the van’t Hoff factor for
trichloroacetic acid.(Kb for water = 0.512Kkg/mol)
Q20) Calculate the amount of KCl which must be added to 1kg of water so that
the f.p. is depressed by 2K.(Kf for water = 1.86Kkg/mol)
Q20) a solution of glycerol (C3H8O3) in water was prepared by dissolving some
glycerol in 500 g of water. this solution has b.p.of 100.420C.what mass of
glycerol was dissolved to make this solution?
(Kb for water = 0.512 K kg /mol. )
Q20) 15 g of an unknown molecular material is dissolved in 450 g of water.
the resulting solution freezes at -0.34 0 C. what is the molar mass of the material?(Kf for

water = 1.86 Kkg /mol)

2012 F
Q9) (a) Define the following terms:
(i)
Van’t Hoff factor
(ii)
Mole fraction
(iii)
Ebullioscopic constant
(b)State Raoult’s law


Q9) the density of water of a lake is1.25 g/ml and 1kg of this water contains 92 g
of Na+ ions.What is the molarity of Na+ ions in the water of the lake?
(at.mass of Na = 23 u )
Q20) At 250C the saturated V.P. of water is 3.165 kPa (23.75 mm Hg). Find the
saturated vapour pressure of a 5% aqueous solution of urea (carbamide) at
the same temperature. ( molar mass of urea = 60.05 g/mol)
Q20) Calculate the F.P. depression expected for 0.0711 m aqueous solution of
sodium sulphate. If the solution actually freezes at -0.320 0C,what is the
actual value of van’t Hoff factor at this temperature?
(Kf for water =1.86Kkg/mol)
2013 AI
Q28) (a) state Raoult’s law for a solution containing volatile components. How does Raoult’s law
become a special case of Henry’s law?
( b) 1.00 g of a non electrolyte solute dissolved in 50 g of benzene lowered the freezing
point of benzene by 0.40 K. Find the molar mass of the solute. (Kf for benzene = 5.12
Kkg mol -1)
Q28) (a) define the following trms:

(i)
Ideal solution
(ii)
Azeotrope
(iii) Osmotic pressure
( b) a solution of glucose (C6H12O6) in water is labeled as 10 % by weight. What
would be the molality of the solution?
(molar mass of glucose = 180 g mol -1)

SOLUTION:
FORMULAE
∆Tb = Kb. wB .1000
MB .wA
∆Tf = Kf. wB .1000
MB .wA
Π.V=


wB . R T
MB

FOR IONIC SOLUTE:
∆Tb =

i Kb * m

∆Tf = i

Kf * m

Π = i CRT
THE VALUE OF
GIVEN


i

MAY BE CONSIDERED 100% IF IONIZATION IS NOT

NOTE: DON’T CHANGE THE UNIT OF ∆Tb OR ∆Tf FROM 0C TO K
 OSMOTIC PRESSURE



IF THE VALUE OF R IS GIVEN 0.083 Lbar /mol.K , Π
bar

SHOULD BE IN




VOLUME OF SOLUTION WOULD BE IN LITRES.



WEIGHT OF SOLUTE SHOULD BE IN gm.



TEMP. SHOULD BE IN KELVIN



3% SOLUTION MEANS w = 3g & Vol. is 100 ml.
 RAOULT’S LAW:

FOR VOLATILE COMPONENT:
P1 = P01 *X1
P2 = P02 * X2
TOTAL V.P. OF SOLUTION

P = P1 + P2

FOR NON VOLATILE COMPONENT:

FOR DILUTE SOLUTION

EXPRESSION OF CONCENTRATION:
MOLE FRACTION

XA = nA/nA +nB

Molality (m) = wB * 1000
MB *wA
Molarity (M) = = wB * 1000
MB *Vol (ml)

(no. of moles present in 1kg solvent)

((no. of moles present in 1L solution)

RELATION SHIP BETWEEN MOLARITY AND MOLALITY
m = M____________
d-MB/100
HENRY’S LAW:
P = KH * X
VAN’T HOFF FACTOR:


i = NORMAL M.M./ ABNORMAL M.M.
= OBSERVED /CALCULATED
i

< 1 (ASSO) i

> 1 (DISSO)

FOR COMPLETE DISSOCIATION
K2SO4 =3

i = 1 (NO ASSO OR DISSO)
i

for KCl = 2

,for CH3COOH = ½ ,for

DEGREE OF DISSOCIATION
α =

i - 1 / n -1

DEGREE OF ASSOCIATION
α =

i - 1 / 1/n -1

Question Bank
(Electrochemistry)

5 marks

SAMPLE PAPER- 1 (OLD)
Q12) Write the chemical equations for the steps involved in rusting of iron. Give
one method to prevent rusting of iron
Q20) For the galvanic cell
Mg(s) + 2Ag+ (0.0001M Mg2+ (0.1M) + 2Ag(s)
E0Mg2+/Mg = -2.36V, E0Ag+/Ag = 0.81V
Calculate Ecell,E0cell. Write cell representation.Will the reaction be
spontaneous?
SAMPLE PAPER- 2 (OLD)
Q29)(a)Calculate the eq. Const. for the reaction Zn + Cd2+  Zn2+ + Cd
E0Cd2+/Cd = -0.403V, E0Zn2+/Zn = -0.763V
(b) When a current of 0.75A is passed through a CuSO4 solution for 25 min.
0.369 g of Cu is deposited at the cathode. Calculate at. mass of Cu
(c ) Tarnished Ag contains Ag2S Can this tarnish be removed by placing
tarnished Ag ware in an Al pan containing an electrolytic solution such
as NaCl.The E0 for half reactions are Ag2S
Ag2S + 2e  2Ag + S2- is –0.17V

Al3+ +3e  Al is -1.66V
Q29) (a) Calculate ∆G0 for the following reaction at 250C
Au + Ca2+(0.1M)  Au3+(1M) + Ca
E0Au3+/Au = +1.5V, E0Cd2+/Cd = -0.403V
Predict whether the reaction will be spontaneous or not at 250C Which of the
above two half cells will act as an O.A. & which one will be a R.A.
(b)The conductivity of 0.001M acetic acid is 4 x 10 –5 S/cm Calculate the
dissociation const. of acetic acid if limiting molar conductivity for acetic acid
is 390.5 Scm2/mol
SAMPLE PAPER- 3 (OLD)
Q10) Molar conductivity vs square root of conc. is given
(a) What can you say about the nature of the two electrolytes A & B


(b) How do you account for the increases in molar conductivity for strong electrolyte
A & weak electrolyte B on dilution.
Q19) (a) A current of 1.5 A was passed through an electrolytic cell containing
AgNO3 soln. With an inert electrodes. The weight of Ag deposited was
1.5 g How long did the current flow?
(b)Write the reactions taking place at the anode & cathode in the above cell.
(c)Give reactions taking place at the two electrodes if these are made up of Ag.
2008 D
Q28) Conductivity of 0.00241M acetic acid solution is 7.896x10 –5 S cm-1
Calculate its molar conductivity in this soln. If limiting molar conductivity
for acetic acid be 390.5Scm2mol-1 What would be the its dissociation
const?
Q28) Three electrolytic cells A,B,C containing soln. of ZnSO4,AgNO3,CuSO4 resp.
are connected in series A steady current of 1.5 A was passed through them
until 1.45 g of Ag was deposited at the cathode of cell B How long did the
current flow? What mass of Cu & what mass of Zn were

deposited in the concerned cell?(Ag = 108, Zn = 65.4 ,Cu =63.5)
Q2) What is primary cell? Give one example
Q10) The conductivity of a 0.2M soln. of KCl at 298 K is 0.0248 Scm-1. Calculate
its molar conductivity.
Q11) Formulate the galvanic cell in which the following reaction tale place
Zn + 2Ag+  Zn2+ + 2Ag
(i)
Which one of its electrodes is negatively charged?
(ii)
The reaction taking place at each of its electrode
(iii) The carriers of current within & out side this cell.
Q2) Express the relation between conductivity & molar conductivity of a soln.
Q10) The resistance of cond. Cell containing 0.001 M KCl soln. at 298 K is 1500
ohm What is the cell const. if the conductivity of 0.001 M soln. at 298 K is
0.146 x 10 –3 S cm-1
2008 AI
Q10) Depict the Galvanic cell for the reaction
Zn + 2Ag+  Zn 2+ + 2Ag
What are the carriers of current inside and outside the cell.State the
reactions at each electrode.
2008 F
Repeated Questions.
2008 D COMPTT
Q6) Illustrate with the help of diagram how the molar conductivities of a
(i)
strong electrolyte (ii) weak electrolyte
vary with dilution of soln. Give reason for this variation
Q20) Calculate E0cell for the following.
2Cr + 3Cd2+  2Cr3+ + 3Cd Calculate ∆G0 & eq. Const. K of the above reaction
at 25 0C (E0Cd2+/Cd = -0.40V, E0Cr3+/Cr = -0.74V)

2008 AI COMPTT
Q28) (a) Explain why electrolysis of an aq. Soln. of NaCl gives H2 at cathode & Cl2
at anode. (E0Na+/Na = -2.71V, E0H2O/H2 = -0.83V, E0Cl2/2Cl- = +1.36V
E02H+/1/2O2/H2O = +1.23V)
(b)The resistance of cond. Cell containing 0.05 M soln of an electrolyte X at 40 0C is
100 ohm The same cell is filled with 0.01M soln. of electrolyte. Y has a resistance of
50 ohm The cond. of 0.05 M soln of electrolyte X is 1.0 x 10 –4 Scm-1 Calculate
(i)cell const. (ii) conductivity of 0.01 M Y soln.(iii) molar conductivity of
0.01M Y soln.


Q28) (a) State Kohlrausch law of independent migration of ions. How can the
degree of dissociation
of acetic acid in a soln. to be calculated from its molar conductivity data.
(b)(i) Formulate the galvanic cell 2Cr + 3Fe2+  2Cr3+ + 3Fe
(ii)Calculate E0cell.
(iii)Calculate Ecell at 250C if [Cr3+] = 0.1M , [Fe2+] = 0.01 M
(E0Cr3+/Cr = -0.74V , E0Fe2+/Fe = -0.44V)
2009 AI
Q9) What type of cell is a lead storage battery? Write the anode & cathode
reaction & the overall reactions occurring in the use of a lead storage
battery.
Q9)Two half cell reactions of an electrochemical cells are given below.
MnO4- + 8H++ 5 e  Mn 2+ + 4H2O E0 = +1.51V
Sn2+  Sn 4+ + 2e E0 = +0.15V
Construct the redox equation from the two half cell reactions & predict if this
reaction favours formation of reactants or product shown in the equation.
Q21) A Cu-Ag cell is set up. The Cu 2+ concentration in it is 0.1M The Ag+
concentration is not known. The cell potential measured 0.422V Determine
concentration of Ag+ in the cell.

Given: (E0Ag+/Ag = 0.80V,E0Cu2+/Cu = +0.80V)
Q21) A voltaic cell is set up at 25 0C with the following half cells
Al/Al 3+ (0.001M) & Ni/Ni 2+ (0.5M)
Write the equation for the cell reaction that occurs when the cell generates
an electric current & determine the cell potential.
(E0Ni2+/Ni = -0.25V, E0Al3+/AlCr = -1.66V)
2009 D
Q28) (a) Define molar conductivity of a substance & describe how far weak &
strong electrolyte,molar cond. Changes with conc. of solute . How is such
change. Explain.
(b) A voltaic cell is set up at 25 0C with the following half cells
Ag+ (0.001M)/Ag & Cu 2+ (0.1M)/Cu
What would be the voltage of this cell? (E0cell. + 0.46V)
Q28)(a) State the relationship amongst cell const. of a cell,resistance of the soln.
in the cell & cond. Of soln. How is molar cond. Of a solute related to cond.
Of its soln.
(b) Calculate K for the reaction Fe+ Cd2+  Fe2+ + Cd
(E0Fe2+/Fe = -0.44V, E0Cd2+/Cd = -0.40V)
Q28) (a) Define molar conductivity.How is it related to cond. Of the related soln.
(b)One half cell in voltaiccell is constructedfrom a silver wire dipped in AgNO 3 soln.
of unknown conc.Its other half cell consists of a Znelectrode dipping in 1.0 M soln. of
Zn(NO3)2.A voltage of 1.48V is measured for this cell. Calculate [Ag+ ]
(E0Zn2+/Zn = -0.76V, E0Ag+/Ag = 0.80V)
Q28)(a) Corrosion is essentially an electrochemical phenomenon. Explain the
reactions occurring during the corrosion of iron kept in an open
atmosphere.
(b) Calculate K for the reaction Fe+ Cd2+  Fe2+ + Cd
(E0Fe2+/Fe = -0.44V, E0Cd2+/Cd = -0.40V)
2009 F
Repeated Questions

2009 D COMPTT
Q28 ) (a) Explain why electrolysis of an aq. Soln. of NaCl gives H2 at cathode &
Cl2 at anode. (E0Na+/Na = -2.71V, E0H2O/H2 = -0.83V, E0Cl2/2Cl- = +1.36V
E02H+/1/2O2/H2O = +1.23V)


(b)The resistance of cond. Cell containing 0.001 M KCl soln. at 298 K is
1500 ohm What is the cell const. if the conductivity of 0.001 M soln. at 298 K is
0.146 x 10 –3 S cm-1
Q28) (a)Calculate emf for the given cell at 5 0C Cr/Cr3+(0.1M)//Fe2+ (0.01M)/Fe
(E0Fe2+/Fe = -0.44V, E0Cr3+/Cr = -0.74V)
(b)Calculate the strength of current required to deposit 1.2 g Mg from
molten MgCl2 in 1 hour. [1F =96500C/mol at.mass Mg =24]
2010 AI
Q2) What is meant by Limiting molar conductivity?
Q11) Given that E0 of metals are K+/K = -2.93V,Ag+/Ag = 0.80V,
Cu2+/Cu = 0.34V,Mg2+/Mg = -2.37V,Cr3+/Cr = -0.74V,Fe2+/Fe = -0.44V.
Arrange these metals in increasing order of their reducing power.
Q11) Two half reactions of an electrochemical cells are given below
MnO4- + 8H+ + 5e  Mn2+ + 4 H2O E0 = +1.51V
Sn2+  Sn4+ + 2e
E0 = +0.15V
Costruct the redox reaction equation from the two half reactions and
calculate the cell potentials and predict if the reaction is reactant or
product favoured?
Q10) Express the relation among cell constant, the resistance of the solution in
the cell and conductivity of solution.How is the conductivity of solution
related to its molar conductivity?
2010 D
Q28)(a)State Kohlrausch law of independent migration of ions.Write an

expression for the molar conductivity of acetic acid at infinite dilution
according to Kohlrausch law.
(b)Calculate limiting molar conductivity for acetic acid. Given that limiting molar
conductivity of HCl,NaCl,CH3COONa are 426,126,91 Scm2 mol-1
respectively.
Q28)(a) Write the anode and cathode reactions and overall reactions occurring
in a lead storage battery.
(b )A Cu-Ag cell is set up [Cu2+]=0.1M [Ag+] is not known. The cell potential
when measured was 0.422V.Determine the concentration of Ag+ ions in the
cell.(Given E0Ag+/Ag = 0.80V, E0Cu2+/Cu = 0.34V)
2010 F
Q9) Write the anode and cathode reactions occurring in a commonly used Hg –
cell. How is the overall reaction represented?
Q20)One Half cell in a voltaic cell is constructed from Ag wire dipped in AgNO3
solution of unknown concentration .The other half cell consists of Zn
electrode in 0.1M solution of Zn(NO3)2.A voltage of 1.48V is measured for this
cell.Calculate concentration of AgNO3 solution.
(Given E0Ag+/Ag = 0.80V, E0Zn2+/Zn = - 0.763V)
Q20) A voltaic cell is set up at 250C with the following half cells Al3+ (0.001M) and
Ni2+ (0.5M) Write equation and determine Ecell.
(Given E0Al3+/Al = -1.66 V, E0Ni2+/Ni = - 0.25V)
NEW SAMPLE PAPER I
Q2) Write the product obtained at anode on electrolysis of conc. H2SO4 using Pt
electrode.
Q9) (i) For a weak electrolyte molar conductance in dilute solution increases
sharply as the concentration in solution is decreased . Give reason.
(ii)
Write overall cell reaction for lead storage battery when the battery is being charged.
Q19)(a)Calculate the charge in Coulombs required for oxidation of 2 moles of
water to oxygen.(1 F = 96500 C/mol)

( b ) Zn/Hg oxide cell is used in hearing aids and electric watches.The following
reactions occur


Zn(s)  Zn2+ + 2 e E0Zn2+/Zn = - 0.76V)
Hg2O+H2O + 2e  2Hg + 2OH- E0Hg+/Hg = - 0.344V)
Calculate (i) standard potential of the cell
(ii ) standard Gibb’s energy
NEW SAMPLE PAPER II
Q12) Describe the construction of a H2 –O2 fuel cell and the reactions taking
place in it.
Q12) Define the terms given below.
(a) Conductivity (b) molar conductivity
Wh at are their units?
Q19) Give reasons:
(a)Why does an alkaline medium inhibit the rusting of iron?
(b) Why does a dry cell become dead after a long time even if it has not been
used?
( c ) Why is Zn better than Sn in protecting iron from corrosion?
NEW SAMPLE PAPER III
Q28) (a) Two electrolytic cells containing AgNO3 solution and dil. HCl solution
were connected in series A steady current of 2.5 A was passed through
them till 1.078 g of Ag was deposited. [Ag = 107.8 g/mol, 1F = 96500 C]
(i)
How much electricity was consumed?
(ii)
What was the weight of O2 gas liberated?
(b) Give reasons:
(i)
Rusting of iron pipe can be prevented by joining it with a piece of Mg

(ii)
Conductivity of an electrolyte solution decreases with the decrease in
concentration.
Q28)(a) What is a fuel cell? What is the main advantage?
( b ) What are the reactions occurring at the cathode and anode of a
Lachlanche cell?
(c) In a button cell widely used for watches and other devices the following reactions takes
place
Zn(s)+Hg2O+H2O  2Hg + 2OH- + Zn2+
Give the cell representation and determine the value of Kc for the above reactions
using the following data. Zn(s)  Zn2+ + 2 e E0Zn2+/Zn = - 0.76V)
Hg2O+H2O + 2e  2Hg + 2OH- ( E0Hg+/Hg = - 0.344V)
Zn2+ + 2 e  Zn(s) ( E0Zn2+/Zn = - 0.76V)
2011 AI
Q28) (a) What type of cell is a lead storage battery? Write the anode & cathode
reaction & the overall reactions occurring in the use of a lead storage
battery.
(b ) Calculate the potential for half cell containing 0.1M K2Cr2O7 (aq) , 0.2M
Cr3+(aq)and 1.0 x 10 -4 M H+.The half cell reaction is
Cr2O7 2- (aq) + 14 H+(aq) + 6 e  2 Cr3+(aq) + 7 H2O(l)
And the standard electrode potential is given as E0 = 1.33V
Q28) (a) How many moles ofHg will be produced by electrolyzing 1M Hg(NO3)2
solution with a current of 2 A for 3 hours? [Hg(NO3)2 = 200.6 g/mol]
(b) A voltaic cell is set up at 250C with the following half cells Al3+ (0.001M) and
Ni2+ (0.5M) Write equation and determine Ecell.
(Given E0Al3+/Al = -1.66 V, E0Ni2+/Ni = - 0.25V)
2011 D
Q2) Express the relation between conductivity and molar conductivity of a
solution held in a cell’
Q9) The chemistry of corrosion of iron is an electrochemical phenomenon.

Explain the reactions occurring in the corrosion of iron in the atmosphere.
Q10) Determine the value of Kc and ∆ G0 for Ni + 2Ag +  Ni2+ + 2Ag


(E0 cell = 1.05V)
2011 F
Q11) Determine the value of Kc and ∆ G0 for Ni + 2Ag +  Ni2+ + 2Ag
(E0 cell = 1.05V)
Q20) A voltaic cell is set up at 25 0C with the following half cells
Al 3+ (0.001 M) and Ni2+ (0.5 M) Write the cell reaction and determine the
cell potential. (E0 Ni2+/Ni = 0.258V , E0 Al3+ /Al = -1.66 V)
2010 D COMPTT
Q28)(a) Explain why electrolysis of aq. solution of NaCl gives H2 at cathode and
Cl2 at anode.Write overall reaction.
( E0 Na+/Na = - 2.71 V,E0 H2O/H2 = - 0.83 V, E0 Cl2/Cl- = + 1.36V,
E0 H+/H2/H2O = + 1.23V)
(b ) The resistance of a conductivity cell containing 0.001 M KCl solution at 298K
is 1500 Ω Calculate the cell constant if conductivity of 0.001M KCl solution at
298 K is 0.146 x 10 -3 S/cm.
Q28) (a) Calculate the emf for the given cell at 250C.
Cr/Cr 3+ (0.1M)//Fe2+(0.01M)/Fe
(E0 Cr3+/Cr = -0.74V , E0 Fe2+ /Fe = -0.44 V)
(b ) Calculate the strength of the current required to deposit 1.2 g of Mg from
molten MgCl2 in 1 hour.( 1F = 96500 C / mol , Mg = 24)
2010 AI COMPTT
Q11) The molar conductivity of a 1.5 M solution of an electrolyte is found to be
138.9 S cm2 /mol Calculate the conductivity of solution.
Q20)What is nickel-cadmium cell? State its one merit and one demerit over lead
storage cell. Write the overall reaction that occurs during discharging of
this cell.

Q20)State and explain Kohlrausch law of independent migration of ions. How
can the degree of dissociation of acetic acid be calculated from its molar
conductance data.
2012 AI
Q9) express the relation among cell constant, resistance of the solution in the
cell and conductivity of the solution. How is molar conductivity of a solution
related to its conductivity?
Q9) the molar conductivity of a 1.5 M solution of an electrolyte is found to be
138.9 Scm2 /mol. Calculate the conductivity of this solution.
Q20) the electrical resistance of a column of 0.05 M NaOH solution of diameter
1 cm length 50 cm is 5.55 x 10 3 ohm. Calculate its resistivity, conductivity
and molar conductivity.
Q20) A voltaic cell is set up at 25 0C with the following half cells
Al 3+ (0.001 M) and Ni2+ (0.5 M) Write the cell reaction and determine the
cell potential. (E0 Ni2+/Ni =- 0.258V , E0 Al3+ /Al = -1.66 V)

2012D
Q28)(a) What type of battery is the lead storage battery ?Write the anode and
cathode reaction and the overall reaction occurring in a lead storage
battery when current is drawn from it.
(b)In the button cell, widely used in watches, the following reaction takes
place.
Zn +Ag2O + H2O Zn2+ + 2Ag + 2OHDetermine E0 and ∆G0 for the reaction
(E0 Ag+/Ag = +0.80V , E0 Zn2+ /Zn = -0.76 V)


Q28)(a) Define molar conductivity of a solution and explain how molar
conductivity changes with change in concentration of a solution for a
weak and a strong electrolyte.
(b)The resistance of a conductivity cell containing0.001M KCl solution at

298 K is 1500Ω.What is the cell constant if the conductivity of 0.001M KCl
Solution at 298 K is 0.146 x 10 -3 Scm-1?
2012F
Q28) (a) What type of battery is the lead storage battery ?Write the anode and
cathode reaction and the overall reaction occurring in a lead storage
battery when current is drawn from it.
(b) A voltaic cell is set up at 250C with the Half cells
Ag+ (0.001M)/Ag and Cu2+(0.1M)/Cu
What should be its cell potential?(E0cell = 0.46V)
Q28) (a) Define molar conductivity of a solution and explain how molar
conductivity changes with change in concentration of a solution for a
weak and a strong electrolyte.
(b)A strip of nickel metal is placed in a 1 molar solution of Ni(NO3)2 and a strip of
silver metal is placed in a 1 molar solution of AgNO3.Anelectrochemical cell is
created when the two solutions are connected by a salt bridge and the two strips are
connected by wires to volt meter.
(i) Write the balanced equation for the overall reaction occurring in the cell and
calculate the cell potential.
(ii)Calculate the cell potential,E at 250C for the cell, if the initial concentration of
Ni(NO3)2 is 0.1 molar and the initial concentration of AgNO3 is 1 molar.
(E0 Ag+/Ag = +0.80V , E0 Ni2+/Ni = - 0.25V)
2013 AI
Q11) the standard electrode potential (E0) for Daniell cell is +1.1 V. Calculate the
∆G 0 for the reaction
Zn(s) + Cu 2+  Zn2+ + Cu(s)
( 1F = 96500 C mol-1)
Q26 ) Calculate emf of the following cell at 25 0C
Ag(s) /Ag + (10 -3M)// Cu 2+ (10 -1 M)/Cu (s)
(Given E 0 Cell= + 0.46 V and log 10 n = n
Formulae

ELECTROCHEMISTRY:
NERNST EQUATION FOR HALF CELL:
E = E0 – 2.303RT log 1
nF
[Mn+]
E = E0 – 0.059
nF

log 1
[Mn+]

NERNST EQUATION FOR CELL POTENTIAL OR e.m.f. OF THE CELL:
E0cell = E0cathde - E0 anode


Zn / Zn 2+ // Cu 2+ / Cu
R
P
R
P

Zn  Zn 2+ + 2e


Cu 2+ + 2e  Cu
0

Ecell = E cell – 2.303RT log [Zn2+]
2F
[Cu2+]



Zn + Cu 2+  Zn 2+ + Cu

Mg / Mg 2+ // Cr3+ / Cr
R
P
R
P
Ecell = E0cell – 2.303RT log [Mg2+] 3
6F
[Cr3+] 2



Pt /Br2 /Br- // H+ / H2 / Pt
P
R
R
P
0
Ecell = E cell – 2.303RT log 1
2F
[Br - ] [H+]2



Pt / I2 / I- // Cl - / Cl2 / Pt
P

R
P
R
Ecell = E0cell – 2.303RT log [Cl -]2
2F
[I - ]2

Mg  Mg 2+ + 2e
Cr 3+ + 3e  Cr
3Mg + 2Cr 3+ 3Mg2++2Cr

2 Br -  Br2 + 2e
2H+ + 2e  H2
2 Br- + 2H+  Br2 + H2

2I -  I2 + 2e
Cl2 + 2e  2Cl 2I- + Cl2  I2 + 2Cl-

EQUILIBRIUM CONSTANT Kc


Ecell = E0cell – 2.303RT log Kc
nF



E0cell x nF
2.303RT
0
0

∆G = - n F E cell



Λm = K x 1000 / C



K = CELL CONSTANT / RESISTANCE



CELL CONSTANT G* = CONDUCTIVITY x RESISTANCE



CELL CONSTANT = l /A



KOHLRAUSCH LAW:

log Kc =

Λ0
Λ 0 Al2(SO4)3 = 2 λ0 Al 3+ + 3 λ0 SO4 2Λ 0 CH3COOH = Λ 0 CH3COONa + Λ 0HCl - Λ 0NaCl


DEGREE OF DISSOCIATION:
α = Λ / Λ0

K = C α 2 / (1 – α)
FARADAY’S LAW
ELECTRIC CHARGE REQUIRED IN F = 1F FOR Na+ , 2 F FOR Ca2+
MnO4 -  Mn 2+ NEEDS 5 F .
Q=I*t

Question Bank
(Chemical Kinetics)

5 marks

SAMPLE PAPER- 1 (OLD)
Q28) For a chemical reaction variation in the [R]  t
(first order graph ln log [R]  t )
(i)
What is the order of reaction
(ii)
What are the units of rate constant k
(iii) Give the relationship between k & t ½
(iv)
What does the slope of the above line indicate?
(v)
Draw a plot log [R0]/[R]  t
Q28) The reaction A+2B 2C+D
Expt.
[A]0
[B]0
1
0.3
0.3

2
0.6
0.3
3
0.3
0.6
4
0.6
0.6
(i)Derive the order of reaction w.r.t.both reactants [A] & [B]
(ii)Write the rate law
(iii)Write the expression for the rate of reaction in terms of A & B

Initial rate
0.96
0.384
0.192
0.768

SAMPLE PAPER- 2 (OLD)
Q10) Consider the reaction AP The change in concentration of A with time is
shown
(i)Predict the order of reaction
(ii)Derive expression for the completion of the reaction
Q24) (a) 2N2O5  4NO2 + O2 is first order reaction with rate constant of
5x10-4 s-1.If initial concentration of N2O5 is 0.25M. Calculate its
concentration after 2 min. Also calculate half life for decomposition of
N2O5
(b)2A +B  3C The rate of appearance of C at time t is 1.3x10-4 mol/L/s
Calculate at this time (i)rate of reaction (ii) rate of disappearance of A

SAMPLE PAPER- 3 (OLD)
Q2) The decomposition reaction ofNH3 gas on Pt surface has a rate const.
K = 2.5x10-4 mol /L/sWhat is the order of reaction?
Q5) What is molecularity of the reaction Cl (g)  ½ Cl2(g)
Q20)(i) Graph of log[Ro]/[R] t is given for first order reaction


(a) What is the relation between slope of this line & rate const.
(b) Calculate the rate const. Of the above reaction if the slope is2x10-4 s-1
(ii) Derive the relation between half life of a first order reaction & its rate
const.
2008 D
Q2) Define the term order of reaction for chemical reaction
Q12) A first order decomposition reaction takes 40 min. for 30% decomposition
Calculate its t1/2 value.
Q13) What is meant by the rate const.’k’of a reaction. If the concentration be
expressed in mol/L units & time in sec.What would be the units for k (i) for a
zero order reaction (ii) for a first order reaction
Q28) (a) Derive the general form of the expression for the half life of a first order
reaction
( b) The decomposition of NH3 on Pt surface is a zero order reaction What are the
rates of production of N2 & H2 if k = 2.5x10-4 mol/L/s
Q28) (a) List the factors on which the rate of a chemical reaction depends?
( b) The half life for decay of radioactive C-14 is 5730 years An
archeological artifact containing wood has only 80% of C-14 activity is found in
living trees. Calculate the age of the artifact.
2008 AI
Q4) Define order of a reaction.
Q9) List the factors which influence the rate of chemical reaction.
2008 F

Q11) A reaction is second order w.r.t. A How is the rate of this reaction altered if
the concentration of A is (i) doubled (ii) reduced to half
Q20) The rate of reaction increases to four times when the temp. is raised from
300K to320K Calculate Ea of this reaction (R = 8.314J/mol/K)
2008 D COMPTT
Q10) Distinguish between order & molecularity of a reaction When could order &
molecularity of a reaction be the same.
Q21) The decomposition of PH3
4PH3  P4 + 6H2 has the rate law r = 6.0x10-4 s-1 & Ea is 3.05 x 105 J/mol
Calculate k at 310 K (R = 8.314J/mol/K)
Q17) List four factors which affect the rate of reaction.
2008 AI COMPTT
Q11) Define order of reaction.How will you prove that a chemical reaction is of
first order
Q10) For a chemical reaction what is the effect of catalyst on the following
(i)
activation energy of the reaction
(ii)
rate const. of the reaction

Q21) For the reaction 2N2O5  4NO2 + O2 at 298 K
Sr.no.

[N2O5] mol/L

1
1.13 x10-2
2
0.84 x10-2
3

0.62 x10-2
Determine (i) order of reaction
(ii)rate const.
(iii) rate law

Rate of disappearance
N2O5(mol/L/min)
34 x 10-5
25 x 10-5
18 x 10-5

of


2009 AI
Q10) Define (a) elementary step in a reaction
( b) rate of reaction
Q19) A first order reaction has a rate const. of 0.0051 min-1 If we begin with
0.10 M concentration of reactant.What concentration of reactant will be
left over after 3 hours
Q20) For a decomposition reaction the values of rate const. k at two different
temp. are given below
K1 = 2.15 x 10-8 L /mol/s at 650K
K2= 2.39 x 10-7 L/mol/s at 700K
Calculate Ea for this reaction (R = 8.314J/mol/K)
Q14) Define activation energy of a reaction and order of reaction
2009 D
Q9) A reaction is second order w.r.t. A How is the rate of this reaction altered if
the concentration of A is (i) doubled (ii) reduced to half
2009 F

All Questions are repeated
2009 D COMPTT
Q4) Why does the rate of a reaction not remain const. throughout the reaction
Process
Q16) Explain the term order of a reaction.Derive the unit for first order rate
const.
Q17) Show that for a first order reaction,the time required for half life period is
independent f initial concentration.
2010 AI
Q28) (a) Explain the terms: (i) Rate of reaction (ii) Activation energy of a reaction
(b) The decomposition of PH3 proceeds according to the following equation.
4PH3  P4 + 6H2 It is found that the reaction follows the following rate
equation Rate = k [PH3] The half life of PH3 is 39.9 s at120 0C
(i) How much time is required for 3/4th of PH3 to decompose?
(ii) What fraction of the original sampeof PH3 remain behind after one
minute.
Q28) (a) Explain the terms: (i) Order of reaction (ii) molecularity of a reaction
( b) The rate of reaction increases four times when the temperature
changes from 300K to 320 K Calculate Ea ,assuming that it does not change with
temperature . ( R = 8.314J/K/mol)
2010 D
Q2) Define order of reaction
Q10) A reaction is of first order in reactant A and second order in reactant
B.How is the rate of this reaction affected when (i) [B] alone is increased to
three times (ii) [A] as well as [B] are doubled.
Q11)The rate constant for a reaction of zero order is 0.003mol/L/s.How long will
it take for the initial concentration of A to fall from 0.1M to 0.075M
Q2) Define rate of reaction.
2010 F
Q2) Identify the order of reaction from the unit for rate constant L/mol/s

Q10) Define (i) elementary reaction
NEW SAMPLE PAPER I
Q3) For the reaction N2 + 3H2 2NH3 If ∆[NH3]/ ∆t = 4 x 10 -8 mol/L/s what is the
value of -∆[H2]/ ∆t


Q10)Sucrose decomposes in acid solution into glucose and fructose according
to the first order rate law with t/2 = 3 hrs.Calculate the fraction of sucrose
which remains after 8 hrs.
Q10) The rate constant of a reaction at 500K and 700K are 0.02 /s and 0.07 /s
resp.Calculate value of activation energy for the reaction
(R = 8.314 J/mol/K)
Q11) For a chemical reaction variation in the [R]  t
(first order graph ln [R]  t )
(i)
What is the order of reaction
(ii)
What are the units of rate constant k
(iii) If the initial concentration of reactant is half of the original concentration how will t/2
change?
(iv)
Draw a plot log [R0]/[R]  t (s)
NEW SAMPLE PAPER II
Q30) (a) For the reaction
C12H22O11 + H2O  C6H12O6 + C6H12O6
Write (i) Rate of reaction expression
( ii) Rate law equation
( iii) molecularity
( iv) order of reaction
( b) The following data were obtained during the first order thermal decomposition of

SO2Cl2 at const. volume.
SO2Cl2 (g)  SO2(g) + Cl2(g)
experiment
Time (s)
Total press. (atm)
1
0
0.5
2
100
0.6
Calculate the rate of reaction when total press. Is 0.65 atm.
Q30) (a) Illustrate graphically the effect of catalyst on activation energy
( b ) Catalysts have no effect on equilibrium const. why?
( c) The decomposition of A into product has value of K as 4.5 x 10 3 /s at 10 0 C and
activation energy is 60 KJ/mol.Calculate the temp. at which the value of K be 1.5 x 10
4
/s
NEW SAMPLE PAPER III
Q13) Consider the decomposition of H2O2 in alkaline medium which is ctalysed by iodide ions.
2H2O2  2H2O + O2
This reaction takes place in two steps as given below
Step I H2O2 + I-  H2O + IOStep II H2O2 + IO- H2O + I- +O2
(a) Write the rate law expression and determine the order of reaction w.r.t. H2O2
(b) What is the molecularity of each individual step.
Q20)In a hydrolysis reaction 5 g ethyl acetate is hydrolysed in presence of dil.
HCl in 300 min. If the reaction is of 1st order and the initial concentration of
ethyl acetate 22 mol/L,Calculate the rate const. of the reaction.
2011 AI
Q1)Define order of reaction.

Q12) What do you understand by the rate law and the rate const. of a
reaction?Identify the order of reaction if the units of its rate const. are
(i)
mol/L/s (ii) L/mol/s
Q13)The thermal decomposition of HCOOH is first order reaction with a rate
const. of 2.4x10 -3 /s at a certain temp. Calculate how long will it take for
3/4th of inititial quantity of HCOOH to decompose. (log 0.25 = -0.6021)
Q12)A reaction is of second order with respect to a reactant.How is the rate of
reaction affected if the concentration of the reactant is reduced to half?
What is the unit of rate const. for such a reaction?


Q1)Define activation energy of a reaction.
2011 D
Q11)Distinguish between rate expression and rate constant of a reaction.
Q20)2N2O5  4NO2 +O2
The first order reaction was allowed to proceed at 40 0Cand the data below were collected.
[N2O5] M
Time (min)

0.4
0

0.289
20

0.209
40

0.151

60

0.109
80

(a) Calculate the rate constant. Include units with your answer.
(b) What will be the concentration of N2O5 after 100 min.
(c) Calculate the initial rate of reaction.
2011F
Q28) Repeated questions
Q28) Repeated questions
2010 D COMPTT
Q4) Why does rate of reaction not remain constant throughout the reaction
Process?
Q16)Explain the term order of reaction Derive the unit for first order rate
constant.
Q17)Show that for the first order reaction the time required for half life period is
independent of initial concentration.
2010 AI COMPTT
Q28) (a) Explain difference between the average rate and instantaneous rate of
Reaction.
(b ) In pseudo first order hydrolysis of ester in water, the following results are
obtained.
T in seconds
[Ester] M

0
0.55

30

0.31

60
0.17

90
0.085

(i)
Calculate the average rate of reaction between time interval 30 to 60 seconds
(ii)
Calculate the pseudo first order rate constant for the hydrolysis of ester.
Q28) (a) Distinguish between molecularity and order of reaction
(b )The activation energy for the reaction 2 HI  H2 + I2 is 209.5 kJ/mol at
581K.Calculate the fraction of molecules having energy equal to or greater
than activation energy (R= 8.31 J/mol/K)
2012 AI
Q10) A reaction is of second order with respect to a reactant.how is the rate
affected if the concentration of the reactant is (i) doubled (ii) reduced to
half?
Q21) the reaction N2 + O2 ↔ 2 NO contributes to air pollution whenever a fuel is
burnt in air at high temperature. At 1500 K, equilibrium constant K for it is
1.0 x 10 -5 . Suppose in a case [N2] = 0.80 mol/L and [O2] = 0.20 mol/L before any
reaction occurs. Calculate the equilibrium concentrations of the reactants and the
product after the mixture has been heated to 1500K.
2012 D
Q10) What do you understand by the ‘order of a reaction’ ? Identify the reaction
order from each of the following units of reaction rate constant:
(i)
L-1mol s-1

(ii)
L mol -1 s-1
Q21)For the reaction 2NO + Cl22NOCl