Question

Using the equation 2H2+O2 = 2H2I, if 192 g if oxygen reacts completely, how many grams of hydrogen must react with it

Answer 1

I assume there is a typo in the equation.  It is H2O instead of H2I.

The ratio of H2 and O2 that react with each other is 2:1.  To find out the grams of H2, we need to first find out the moles of O2 and H2.

Moles of O2 = mass of O2/molar mass of O2 = 192g/32g/mol = 6 mol.  Therefore, the moles of H2 = 6mol *2 = 12 mol.

So the mass of H2 that reacts with O2 = moles of H2 * molar mass of H2 = 12 mol * 2 g/mol = 24 g