Question

10 mL of liquid carbon disulphide (specific gravity 2.63) is burnt in oxygen. Find the volume of the resulting gases measured at STP.

• A. 23.25 L
• B. 22.26 L
• C. 23.50 L
• D. 20.08 L

Answer 1

Answer: (A)

1 mL of CS₂ weighs 2.63 g
10 mL of CS₂ weighs 26.3 g
$\begin{array}{ccccc}C{S}_2& +& 3O_2& \to & \\ 12+\left(2\times 32\right)& & & & \\ 76g& & & & \end{array}\underset{67.2L}{\underbrace{C{O}_2+2S{O}_{2}22.4L44.8L}}$
$\because$76 g of CS${}_2$ will yield 67.2 L of a mixture of CO${}_2$ and SO${}_2$ at STP
$\because$ 26.3 g of CS${}_2$ would yield $\frac{67.2}{76}\times 26.3$ = 23.25 L