Question

In the reaction 2 HgO --> 2 Hg + O2, how many moles of O2 are produced when 9.3 moles of HgO are decomposed?

Answer 1

We write down the reaction to start:

2 HgO => 2 Hg + O2 (don't forget to balance it first)

We only work with moles as units.

Procedure: Use stoichiometry

2 x 1 mole HgO ---------- 1 mole O2

9.3 moles HgO ---------- x

x = 4.7 moles O2

Answer: 4.7 moles