Question

An aqueous solution of 2.7mmol of magnesium hydroxide, Mg(OH)2​, is titrated with acetic acid. How many equivalents of acetic acid were used for titration?

How many moles of acetic acid were used?

Answer 1

The balanced chemical equation between Mg(OH)2 and acetic acid is shown below,

Mg(OAc)2 2H20 2 CH3COOH M g(OH)2

It is clear from the balanced chemical equation, that 1 equivalent of Mg(OH)2 requires 2 equivalents of acetic acid. Therefore, 2 equivalents of acetic acid is used for titration.

From the balanced chemical equation, 1 mole of Mg(OH)2 requires 2 moles of acetic acid. Therefore we can consider,

number of mmoles of acetic acid = 2 x Number of moles of Mg(OH)2

= 2 x 2.7 = 5.4 mmol of acetic acid

Therefore, 5.4 mmoles of acetic acid will be used.