Question

What is the concentration of `1.12*L` of carbon dioxide gas?

Answer 1

Approx. `0.9*mol*L^-1`

Explanation:

`CaCO_3(s) + 2HCl(aq) rarr CaCl_2(aq) + H_2O(l) + CO_2(g)uarr`

We assume that the gas was collected at `298*K` and at `1` `atm` pressure. Under these conditions, `1` `mol` of gas, any gas, has a volume of `25.4*L`

So moles of `CO_2` `=` `(1.12*cancelL)/(25.4*cancelL*mol^-1)` `=` `4.41xx10^-2*mol`

Now form the stoichiometric equation, for each mole of gas produced, there were 2 mole of hydrochloric acid.

Thus `"Concentration"` `=` `(2xx4.41xx10^-2*mol)/(0.100*L)` `=` `??*mol*L^-1`

This is a slight over estimate in that the gas collected is saturated with water vapour. This saturated vapour pressure should be subtracted from the pressure.