Question

in the combustion of hydrogen gas, hydrogen reacts with oxygen from the air to form water vapor. if you brun 31.0 g of hydrogen and produce 277 g of water, how much oxygen reacted?

Answer 1

The mass of O_2 reacted is 246 g.

According to the Law of Conservation of Mass,

Mass of H_2 + mass of O_2 = mass of H_2O

∴ Mass of O_2 = mass of H_2O – mass of O_2 = 277 g – 31.0 g = 246 g O_2