Water and Solutions
Acids and Bases
Nearly 70% of your body
is water
Functions of Water
Water helps body with
homeostasis
Helps retain body heat
Helps cool body
Cohesion and Adhesion
Cohesion is attraction
between substances of the
same kind –
Water is cohesive – it is
attracted to itself
Adhesion is attraction
between substances of
different kinds
Water is adhesive – it is
attracted to other polar
substances
Adhesion – allows for
capillary action that allows
water to move up in the
stems of plants
Aqueous Solutions
Solution – a mixture in
which one or more
substances are evenly
distributed in another
Aqueous solution – a
mixture in which one or
more substances are evenly
distributed in water
Polarity of water allows
many substances to
dissolve in it.
Acids and Bases
Water can disassociate into
ions:
MORE hydrogen ions = ACID
H2O  H+ + OH-
Water has low number of
Hydroxide (OH-) and
hydrogen ions (H+) in equal
numbers
Acids – form H+ in solution
Bases – form OH- in
solution
MORE hydroxide ions = BASE
pH Scale
Based on concentration of hydrogen ions
All solutions have pH between 0 and 14
Pure water pH = 7
Acidic solutions pH less than 7
Basic solutions pH more than 7
Each whole number represents a factor of 10 on pH
scale. pH 5 has 10 times more hydrogen ions than pH
6.
Common Acids and
Bases
pH Scale
pH Lab
Predict pH of various household substances and test
using pH paper