Question

The reaction between `H_2` and `O_2` produces 13.1 g of water. How many grams of `O_2` reacted? `2H_2(g) + O_2(g) -> 2H_2O(g)`?

Answer 1

Approx. `12*g` of dioxygen gas.

Explanation:

There are `(13.1*g)/(18.01*g*mol^-1)=0.727*mol` of water product.

`H_2(g) + 1/2O_2(g) rarr H_2O(l)`

Given the stoichiometry of the reaction, there were necessarily `0.727*mol` dihydrogen reactant, and `(0.727*mol)/2` dioxygen reactant. I speak of dihydrogen, dioxygen etc. because I wish to avoid the confusion of mistaking atoms for molecules and vice versa.

`"Mass of dioxygen reactant "=(0.727*mol)/2xx32.00*g*mol^-1=??g`