Question

A certain sample of coal contains $1\%$ of sulphur by weight. What is the weight (in kg) of sulphur dioxide produced when $2\times {10}^6$ kg of this coal is burnt?

• A. $2\times {10}^4$
• B. $4\times {10}^4$
• C. $4\times {10}^5$
• D. $2\times {10}^5$

Answer 1

The correct option is B $4\times {10}^4$

Given, a sample of coal contains $1\%$ of sulphur by weight.
Therefore, weight of sulfur in $2\times {10}^6$ kg of coal is $2\times {10}^6\times \frac{1}{100}=2\times {10}^4$ kg.
The reaction is $S+O_2\to S{O}_2$.
Weight of sulfur dioxide produced when $2\times {10}^6$ kg of coal is burnt will be $2\times {10}^4\times \frac{64}{32}=4\times {10}^4$ kg.