Experiment 8 - Equivalent Weight of an Unknown Acid
Prepare a solution of an unknown acid, and then use a standardized sodium
hydroxide solution to determine the equivalent weight of the unknown acid.
In acid-base reactions the equivalent weight of an acid is the
mass of the acid that will react with one mole of sodium hydroxide, NaOH. For
hydrochloric acid, HCl, the equivalent weight equals 36.5 grams (the molar mass)
since one mole of the acid reacts with one mole of sodium hydroxide.
The equivalent weight of sulphuric acid, H2SO4,
is 49.0 grams since half a mole of sulphuric acid reacts with one mole of sodium
In this lab, you will be given an acid of unknown identity. The
balanced chemical equation for the neutralization of the unknown acid with NaOH
has a 1:1 mole ratio of unknown acid:base.