Question

The % loss in mass after heating a pure sample of potassium chlorate (Mol. mass = 122.5) will be:

• A. 12.25
• B. 24.5
• C. 39.17
• D. 49

Answer 1

Answer: (C)

39.17

$2KCl{O}_3\to 2KCl+3O_2$
$2\times 122.5$ grams shows a wieght loss of $3\times 32grams$
So 245 grams of $KCl{O}_3$ is 100%
96 grams of $O_2$ is X%
$x=\frac{100\times 96}{245}=39.17$.
Hence option C is correct.