Question

The active mass of $64g$ of HI in a two litre flask would be

• A. 2
• B. 1
• C. 5
• D. 0.25

Answer 1

Answer: (D)

Active mass is taken as molar concentration i.e number of moles per litre
$\therefore$ Active mass of $HI=\frac{64}{128}\times \frac{1}{2}=0.25$
(Molar mass of $HI=128$ )