ĐỀ THI NĂNG KHIẾU HOAHOC

PHoNG GrAo DUC vA DAo rAo rp eEN rRE
rntIOITc THCS THANH PHo BEN TRE
ON TTTT CHSN HQC SINH

XANC KHIEU KHOI 8, NAM HQC
Ngiy thi27 thrlng 3 nIm 2014
Mdn: HOA HOC
Thdi gian 90 pilit

2OT3

- 2OI4

CAu 1: (a diOm)

c6 bon l9 khong nhdn chria cdc dung dich Narcor; MgSoo;

Bacl

2,HCl.

Kh6ng c6 h6a ch6t ndo kh6., n6u phuongphiry nhan bi6t m6i dung dich.
Cfru 2: (a di6m): C6n bing cdc phtnring h6a hoc sau:

al
bl
cl
dl

FerO,

+Al t" >Fe,O- + AlrO,

) --bFer(SOo), + SO, + HrO
A1+HNO, +Al(NOr), +NO + NrO +HrO
Fe*O, + HrSOo( d6c

C,HyO,+o, -I--+Cor+Hro

Cfru 3: (a diOm):
1/ Cho 0,65 gam Znt6c dUng voi7,3 gam HCl.
al Chdtndo cdn du sau phdn fing? C6 kh5i luq,ng ld bao nhi6u gam?
b/ Tinh the tfch khi hidro thu dusc d dkrc ?
2lHdatan hodn todn3,22ghdn hqp X gdm Fe, Mg vdZnbdng mQt lugng vua
dri dung dich H2Soa lodng, thu dugc 1,344LitIH2( cr dktc) vd dung dich chira m gam
,..
mudi. ^,
Tfnh gi6 tri cria m?
Cfru 4: (a diem):
Cdc thi nghiQm hda hgc sau:
llD6tP trong 1o c6 sEn 1 it nudc sit sau d6 dfly nrit lpi rOi tac d6u cho den khi
kh6i trdng tan h€t vdo trong nu6c. Cho mAu quj,tfm vdo dung dfch trong lo.
2l Cho Znvdo dd H2SO4 lodng , d6n khi sinh ra vdo 5ng nghiQm chria s8n mQt
it 02 .Dua
,ua ong
6ng ngruem
nghiQm lgi
gal]. ngQn lua
Lat gAn
hia oen
ddn con.

c6n.
3/ Cho m6t mAu Na vdo c6c nu6c dO s8n mAu
gid quj,tfm.
ndu gi6y
4l Cho mQt mAu Ca(OH)2vdo nudc, khu6'yy d6u rdi
r6i dem lgc,
lgc sau d6 th6i khi th0
vdo nu6c loc.
NCu c6c hiQn tuqng xhy rutrong cdcthinghiCm, vitit phucrng trinh ph6n img vd
cho bitit cdc phinrlng d6 thuQc ph6n ring h6a hoi ndo?
CAU 5: (a di6m) C6 2 thi nghi€m sau:
Thi nghiQm 1: cho a gam sat hda tan trong dung dich HCl. Sau khi cd can
dung dfch thu dugc 3,1 gam chiltrhn.
Thi nghiQm 2: N6u cho a gam sdt vd b gam Magie vdo dung dich HCI ( cing
v6i lu-o. ng nhu thi nghiQm 1). Sau khi cO cpn dung dich thu dugc 3,34 gam ch6t rdn vd
448 ml khi hidro (dktc).
Tinh a , b vd kh6i luqn g circ mu6i tao thdnh.
( Cho

Mg: 24,C1:35,5 , H:1, Fe: 56, Cu:64, 0:16, K:39, N:

14

,Ztr65 , S:32)