What mass of oxygen will react with hydrogen with a chemical amount of 5 mol?

Reaction: 2H2 + O2 = 2H2O;

According to the coefficients of the reaction equation, it can be seen that 2 times less oxygen is involved than hydrogen, which means 5 mol (hydrogen): 2 = 2.5 mol (oxygen).

Molar mass (M) of oxygen as an element = 16 g / mol, in a gaseous state (O2) =

= 16 g / mol * 2 = 32 g / mol.

The mass of oxygen in a given reaction: m (O2) = n * M = 2.5 mol * 32 g / mol = 80 g.

Answer: m (O2) = 80 g.