Question

Calculate the moles of $S{O}_2$ produced by burning $1.0$ metric ton $\left({10}^{3}kg\right)$ of coal containing $0.05\%$ by mass of pyrites impurity.

• A. $8.32$
• B. $4.16$
• C. $12.48$
• D. $2.08$

Answer 1

The correct option is A $8.32$

The mass of $Fe{S}_2$ present in 1000 kg of coal is ${10}^6\times \frac{0.05}{100}=500$g.
The molar mass of $Fe{S}_2$ is 120.
The number of moles of $Fe{S}_2$ in 500 g are $\frac{500}{120}=4.17$ moles.
2 moles of $Fe{S}_2$ will produce 4 moles of $S{O}_2$.
1 mole of $Fe{S}_2$ will produce 2 moles of $S{O}_2$.
4.17 moles of $Fe{S}_2$ will produce $2\times 4.17=8.32$ moles of $S{O}_2$.