Question

Suppose you are provided with a 30.86 g sample of potassium chlorate to perform this experiment. What is the mass of oxygen you expect

to release upon heating?

Answer 1

The mass of oxygen is 12.10 g.

Step-by-step explanation:

The decomposition reaction of potassium chlorate is the following:

2KClO₃(s) → 2KCl(s) + 3O₂(g)

We need to find the number of moles of KClO₃:

`\eta_{KClO_(3)} = (m)/(M)`

Where:

m: is the mass = 30.86 g

M: is the molar mass = 122.55 g/mol

`\eta_{KClO_(3)} = (30.86 g)/(122.55 g/mol) = 0.252 moles`

Now, we can find the number of moles of O₂ knowing that the ratio between KClO₃ and O₂ is 2:3

`\eta_{O_(2)} = (3)/(2)*0.252 moles = 0.378 moles`

Finally, the mass of O₂ is:

`m = 0.378 moles*32 g/mol = 12.10 g`

Therefore, the mass of oxygen is 12.10 g.

I hope it helps you!