Question

$5g$ of each of the following gases at $87^{\circ }C$ and $750mm$ pressure are taken. Which of them will have the least volume?

• A. $HF$
• B. $HCl$
• C. $HBr$
• D. $HI$

Answer 1

Answer: (D)

Number of moles $\propto \frac{1}{\text{ Molecular weight }}$

$\therefore$ HI will have the least number of moles and hence least volume.