Question

Through electrolysis, a student collects 6.6 g of hydrogen gas and 52.4 g of oxygen gas. The reaction was allowed to proceed to completion. What was the mass of water initially present?

Answer 1

Answer: 59 grams

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

$2H_2O\rightarrow 2H_2+O_2$

Given: mass of hydrogen = 6.6 g

mass of oxygen = 52.4 g

Mass of products = Mass of hydrogen + mass of oxygen = 6.6 +52.4 = 59 g grams

Thus mass or reactant = mass of water

Mass of reactants = mass of products = 59 g

Thus the mass of water initially present was 59 g.