Answer to Question #109782 in Chemistry for Mary Dixon

Question

When heated, KClO3 decomposes into KCl and O2.

2KClO3= 2KCl + 3O2
If this reaction produced 17.2 g of KCl, how many grams of O2 were produced?

Answer 1

According to the reaction, number of moles of KCl and O₂ produced during the decomposition must be equal. As a result, the mass of oxygen equals:

m(O₂) = [m(KCl) × 3 × Mr(O₂)] / [2 × Mr(KCl)] = [17.2 g × 3 × 32 g/mol] / [2 × 74.5 g/mol] = 11.1 g

Answer: 11.1 g