ACIDS & PH
pH
9.0
Acids release hydrogen ions in water
nitric acid droplet
from acid rain
surface
water
Amount of hydrogen ion
in a small pond
A hydrogen ion is a single proton. In water, it is always bound to a water molecule.
H
H+
proton
O
H
O
8.0
Sea water
7.0
Pure water without carbon dioxide
1m
H
3m
3m
H+
H+
water molecule
Strongly alkaline lakes
nitrate
ion
hydrogen
ion
H
THE pH SCALE
NO3-
H+
HNO3
H+
hydrogen ion
bound to water
1 mg
Molecules and ions are counted in moles. One mole is (about) 600,000,000,000,000,000,000,000
(6 x 10 23) molecules.vv
1 gram of protons
Zooplankton diversity begins to decline
Average pH of Hudson
H+ = 1 mole of hydrogen ion = 6 x 10 23 protons
Critical pH of blacknose dace
A hydrogen ion concentration of 1 mole per liter is a 1 molar solution.
10 mg
6.0
Critical pH for sensitive mayflies
pH is a measure of the concentration of hydrogen. A 1 molar solution has a pH of 0.
1 gram of
protons
H+
pH 0
1 liter of water
0.1 gram
of protons
1 liter of water
pH 1
0.01 gram
of protons
Pure water in equilibrium with atmosphere
Critical pH for brook trout
pH 2
100 mg
5.0
1 liter of water
Critical pH of yellow perch
Average rain in central Adirondacks
The pH goes up 1 unit every time the concentration of hydrogen ions goes down 1 unit.
Pure water, which is slightly ionized, has a hydrogen ion concentration of 1/10,000,000 molar and a pH of 7.
HOH
H+
OH-
water
hydrogen
ion
hydroxol
ion
1 x 10 -7
grams of
hydrogen
ions
H+
1 liter of water
1g
4.0
Lowest pH lake in Adirondacks, 1986
pH 7
10 g
3.0
1000