chemistry homework

Question

If you burn 34.3 g of hydrogen and produce 306 g of water, how much oxygen reacted?

Mass of oxygen= g?

Answer 1

The Law of Conservation of Mass states that matter can be neither created nor destroyed. For this reason, the mass on the left side of an equation equals the mass on the right side of the equation.

Therefore, 34.3 g hydrogen + the mass of oxygen = 306 g water

Rearranged, the mass of oxygen = 306 g water - 34.3 g hydrogen = 272 g