Question

What mass of oxygen is needed for the complete combustion of `8.90 * 10^-3` `g` of methane?

Answer 1

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

Explanation:

`"Moles of methane"` `=` `(8.90xx10^-3*g)/(16.04*g*mol^-1)` `=` `??` `"moles"`

Given the stoichiometric equation, quite clearly, we need twice this molar quantity of dioxygen gas for complete combustion:

`2xx(8.90xx10^-3*g)/(16.04*g*mol^-1)xx32.00*g*mol^-1" dioxygen gas"`

`=` `??g` `"dioxygen gas"`.