Fig. 2.8
Tap. 26a
Tap. 26b
Fig. 2.9
Fig. 2.10
In Neutral solutions there will
be a number of OH– ions equal to
the number of
H+ ions
Fig. 2.11
In Acidic solutions there will always be more H+ ions than there are
OH- Ions
Fig. 2.12
In Basic (alkali) solutions there is always a greater number of OH- ions than there
are H+ Ions
Tap. 28
Even in pure distilled water, the water molecules will dissociate, but the number of H+ ions will
always equal the number of OH- Ions
In one liter of distilled water there will be 10-7 X Avagadros number (6.02 X 1023 ) of H+ ions
10-7 = 0.000 0001 X Avagadros number of H+ ions per liter. This is a pH of “7” . So something with a pH of 2 would be 10-2 = 0.01 X Avagadros number of H+ ions
per liter. That means the pH number of 2 has way more H+ ions, way more acidic
Fig. 2.13
Tap. 29
Buffers are chemicals that take up either excess H+ ions or excess OH- ions to help
maintain a given pH at the level it is supposed to stay at.
In the above reaction, Bicarbonate ions act as a buffer to take up the excess H+ ions. During this reaction Carbonic Acid is produced, when
Carbonic Acid is carried to the lungs it will dissociate into H2O and CO2 and be exhaled from the body. See Below
H2CO3 H20 + CO2
Fig. 2a