Question

At a given temperature, an `8*mol` quantity of methane that occupies a volume of `200*L` is combusted with stoichiometric oxygen gas. Can you address...?

`"(i) the molar quantity of dioxygen gas required for equivalence;"`
`"(ii) the volume of dioxygen gas required for equivalence;"`

Answer 1

We need a stoichiometrically balanced equation:

`CH_4(g) + 2O_2(g) rarr CO_2(g) +2H_2O(l)`

Explanation:

The balanced chemical equation tells us that `"1 mole/1 equiv"` of methane gas requires `"2 moles/2 equiv"` of dioxygen gas for complete combustion.

We started with `4.0*mol` of methane, and thus we require `8.0*mol` of dioxygen gas to combust this completely. This represents a mass of `4.0*cancel(mol)xx16.01*g*cancel(mol^-1)=64.0*g` methane, and how many grams of dioxygen gas?

Since the volume is specified, there thus must be TWICE the volume of dioxygen compared to methane for stoichiometric equivalence.