Question

Question #2db9c

Answer 1

It's answer 1 (500 `cm^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 `0.050/0.1` = 0.5 litre or 500 `cm^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!