What mass of NO2 can be produced from 5 grams of oxygen

Question

Stiochiometry Pratice questions.

Answer 1

How many moles of O are in 5 g of O? 5 g O x 1 mol O / 16 g = 0.3125 mols O

How many moles of O are in 1 mol NO2? 2 moles of O per mol NO2

0.3125 mols O x 1 mol NO2 / 2 mol O = 0.156 mols NO2 = 0.2 mols NO2 (1 sig. fig.)