Neutralization
Reactions
Name
____________________________
Date _____
Acid-base
reactions are very common. In liquid solutions, acids increase the hydrogen ion (H+) concentration. On the other hand bases increase the hydroxide ion (OH-) concentration. When an acid
and a base react in a solution the H+ and OH- ions combine to form water. These
ions thus "neutralize" one another:
H+
+ OH- ----> H2O
A neutralization
reaction is when an acid and a base
react to form water and a salt and involves the combination of H+ ions and OH-
ions to generate water.
The
neutralization of a strong acid (HCl) and strong base (NaOH) has a pH equal to
7. (If you have equal amounts of
each and they are of equal strength/concentration/Molarity.)
HCl + NaOH ------> H2O + NaCl
The
neutralization of a strong acid and weak
base will have a pH of less than 7,
so the solution is still ACIDIC but less acidic than it was before. It is more neutral.
The
neutralization of a strong BASE and a weak acid is similar. The result will be closer to neutral
but still a base.
NaOH + vinegar ---------> Weak Base (pH= 8-9)
Some important neutralization reactions:
1. We take antacid tablets like Tums to
neutralize stomach acid. The
antacid usually contains NaHCO3 which is a weak base.
2. Also in the digestive tract, neutralization reactions are
used when food is moved from the stomach to the intestines. In order for the
nutrients to be absorbed through the intestinal wall, a basic environment is
needed, so the pancreas produce an antacid bicarbonate to neutralize the acidic
food from the stomach.
3. Another common use is in fertilizers and
control of soil pH. Fertilizers
that improve plant growth are made by neutralizing sulfuric acid (H2SO4) or
nitric acid (HNO3) with ammonia gas (NH3), making ammonium sulfate or ammonium nitrate.
These are salts utilized in the fertilizer.
