Question

From the complete combustion of $64$ grams of sulfur what volume in litres of $S{O}_2$ will form?

• A. $2.00$
• B. $11.2$
• C. $44.8$
• D. $126$
• E. $158$

Answer 1

Answer: (C)

$44.8$

$S+O_2\to S{O}_2$
The atomic mass of $S$ is 32 $g/mol$. The number of moles is obtained by dividing mass with atomic mass. Number of moles of S $=\frac{64g}{32g/mol}=2mol$. The complete combustion of 1 mole of $S$ gives 1 mole of $S{O}_2$. Hence, the complete combustion of 2 moles of $S$ will give 2 moles of $S{O}_2$. At $STP$, 1 mole of $S{O}_2$ will occupy a volume of 22.4 $L$. Hence, 2 moles of $S{O}_2$ will occupy a volume of $2\times 22.4=44.8L$