Question

A certain amount of potassium chlorate on thermal decomposition gives oxygen which is sufficient for the combustion of ethane. When the products are cooled, the volume of the gaseous product is v ml. Identify the correct sequence of steps for the calculation of the mass of potassium chlorate
(a) Calculation of oxygen required for the combustion of ethane.
(b) Calculation of the amount of the ethane subjected to combustion from the volume of gaseous product.
(c) Calculation of potassium chlorate which can give the required amount of oxygen.
(d) Identification of the products of combustion of ethane and the product left after the cooling of products.

• A. a b c d
• B. d b a c
• C. b c a d
• D. d a c b

Answer 1

The correct option is B d b a c

Thermal decomposition of $KCl{O}_3$

$2KCl{O}_3\left(s\right)\to 2KCl\left(s\right)+3O_2\left(g\right)$

Combustion of ethane $C_2{H}_6\left(g\right)+\frac{7}{2}{O}_2\left(g\right)\to 2C{O}_2\left(g\right)+3H_{2}O$

To find the mass of potassium chlorate

First we will identify the products of combustion of ethane and the products left after cooling of products

We required the products left after cooling so that the mass of the product is measured correct

From the volume of gases formed in the combustion of ethane, we can find the mass of ethane

From the mass of ethane we can find the amount of oxygen which is required to form products

Since the oxygen required for combustion of ethane is formed from the thermal decomposition of $KCl{O}_3$. So the amount of oxygen used in combustion of ethane is the same which is formed from the thermal decomposition of $KCl{O}_3$.

From the amount of oxygen, we can find the mass of potassium chlorate.