Small amounts of oxygen gas can be produced for laboratory use by heating potassium chlorate, which causes it to decompose by the following reaction: ___KClO₃(s) $\rightarrow$_{____}KCl(s) + ___O₂(g) (unbalanced) Balance the equation, and determine the mass of oxygen that should be formed if 15.0 g of potassium chlorate decomposes.

Question

Quizplus · Accepted Answer

The balanced equation is: 
2KClO3(s) → 2KCl(s) + 3O2(g)

The molar mass of KClO3 is 122.55 g/mol, so 15.0 g is equal to 0.12255 mol.

According to the balanced equation, 2 moles of KClO3 produces 3 moles of O2. Therefore, 0.12255 mol of KClO3 should produce:

(3 mol O2 / 2 mol KClO3) x 0.12255 mol KClO3 = 0.183825 mol O2

The molar mass of O2 is 32.00 g/mol, so 0.183825 mol is equal to 5.88 g.

Therefore, the mass of O2 produced when 15.0 g of KClO3 decomposes is 5.88 g. The correct answer is (D).

Small Amounts of Oxygen Gas Can Be Produced for Laboratory →\rightarrow→

Small Amounts of Oxygen Gas Can Be Produced for Laboratory $\rightarrow$