# Question #2db9c

Aug 10, 2016

It's answer 1 (500 $c {m}^{3}$)

#### Explanation:

Each mole of calcium hydroxide yields 1 mole of calcium carbonate on reaction with carbon dioxide.

50 ml of 0.5M calcium hydroxide solution contains (50/1000) . 0.5 = 0.025 mol

For every mole of calcium carbonate on you need 2 moles of hydrochloric acid, so if you had 0.025 mol of calcium carbonate, you would have used 0.050 mol of hydrochloric acid.

The volume is therefore $\frac{0.050}{0.1}$ = 0.5 litre or 500 $c {m}^{3}$

(Molarity or normality? In this question it's irrelevant as hydrochloric acid is monoprotic). The atomic mass of calcium is a red herring as well!