C3H8(g) + 5 O2(g) >3 CO2 (g)+ 4H2O (g) If the experiment contains 75.0 grams of O2, how many grams of H2O should be produced?

33.75g H2O

Explanation:

75g O2 (1 mol O2/32g O2) (4 mol H2O/5 mol O2) (18g H2O/1 mol H2O) = 33.75g H2O

This is a stoichiometric calculation in which 75 is multiplied by 1, 4, and 18 (the top numbers), and then divided by (32 x 5 x 1), which are the bottom numbers.

Stoichiometry is super fun once you get the hang of it!!