On food and cooking the science and lore of the kitchen ( PDFDrive ) 1499

Lemonjuice 2.1
Orangejuice 3.0
Yogurt 4.5
Blackcoffee 5.0
Milk 6.9
Eggwhite 7.6–9.5
Bakingsodainwater 8.4
Householdammonia 11.9

Acids. Acids are molecules that release
reactive hydrogen ions, or protons, in water,
where neutral water molecules pick them up
and become positively charged. The acids
themselves become negatively charged. Left:
Wateritselfisaweakacid.Right:Aceticacid.
TheDefinitionofpH
The pH of a solution is defined as “the


negative logarithm of the hydrogen ion
concentration expressed in moles per
liter.” The logarithm of a number is the
exponent, or power, to which 10 must be
raised in order to obtain the number. For
example,thehydrogenionconcentrationin
purewateris10-7molesperliter,sothepH
of pure water is 7. Larger concentrations
are described by smaller negative
exponents, so a more acidic solution will
have a pH lower than 7, and a less acidic,
more basic solution will have a pH higher

than7.Eachincrementof1inpHsignifies
an increase or decrease in proton
concentration by a factor of 10; so there
are 1,000 times the number of hydrogen
ionsinasolutionofpH5asthereareina
solutionofpH8.
Fats,Oils,and
Relatives:Lipids