Question

At ${48}^{o}C$, the vapour pressure of pure $C{S}_2$ in $850\text{torr}$. A solution of $2.0\text{g}$ of sulphur in $100\text{g}$ of $C{S}_2$ has a vapour pressure $844.9\text{torr}$. Determine the atomicity of sulphur molecule.

• A. $16$
• B. $8$
• C. $4$
• D. $10$

Answer 1

The correct option is B $8$

By using formula,
$\frac{P^o-P}{P}=\frac{n}{N}=\frac{w\times M}{m\times W}$
By substituting the values, we get
$\Rightarrow \frac{850-844.9}{844.9}=\frac{2\times 76}{m\times 100}$
$m\approx 252\therefore \text{Atomicity of Sulphur molecule}=\frac{252}{32}=8$