Question

How many mols `CaCO_3` can be dissolved in .0250 mol `HCl` in the equation `CaCO_3 + 2HCl -> CaCl_2 + H_2O + CO_2`?

Answer 1

`0.0125molCaCO_3`

Explanation:

The equation says

`CaCO_3 + 2HCl`,

which means that for every `2` moles of `HCl` there is one of `CaCO_3`. This is called the molar ratio, in this case `2:1`.

We know that there are `0.0250` moles of `HCl`, which is equal to two parts in the ratio. If `0.0250` is two parts, then one part must be `0.0125`.

And, since there is only one part of `CaCO_3` in the ratio, then you can dissolve `0.0125` moles of `CaCO_3` in `0.0250` moles of `HCl`.