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Question

Potassium superoxide, KO₂, reacts with carbon dioxide to form potassium carbonate and oxygen: 4KO₂ + 2CO₂ —> 2K₂CO₃ + 3O₂

This reaction makes potassium superoxide useful in a self-contained breathing apparatus. How much O₂ could be produced from 2.49 g of KO₂ and 4.44 g of CO₂?

___ g

Answer 1

Hello, Kirsten,

J.R. has the correct answer. I might only add that pay attention to the units. The equation:

O₂ produced = 0.0350 mol KO₂ x 3 mol O₂/4 mol KO₂ = 0.0263 mol O₂

contains a conversion for the number of moles of O2 that are produced per mole of KO2 (3mol O2/4 mol KO2), based on the balanced equation.

Thanks, J.R.

Bob

Answer 2

4KO₂ + 2CO₂ —> 2K₂CO₃ + 3O₂ ... balanced eq

Find the limiting reactant:

2.49 g KO₂ x 1 mol KO₂/71.1 g = 0.0350 mole

4.44 g CO₂ x 1 mol CO₂/44 g = 0.100 mol

Based on 4 mol KO₂ needed for 2 mol CO₂ LIMITING REACTANT = KO₂

O₂ produced = 0.0350 mol KO₂ x 3 mol O₂/4 mol KO₂ = 0.0263 mol O₂.

mass O₂ = 0.0263 mol O₂ x 32 g/mol = 0.842 g O₂