Q. For the reaction,$Cl_{2} + 2l^{-} \rightarrow I_{2} + 2Cl^{-}$,the initial concentration of $I^{-}$ was 0.20 mol $L^{- 1}$ and the concentration after 20 min was 0.20 mol $L^{- 1}$.Then the rate of formation of $I_{2}$ in mol $L^{- 1}$ would be

A) $1 \times 10^{- 4}$
B) $5 \times 10^{- 4}$
C) $1 \times 10^{- 3}$
D) $5 \times 10^{- 3}$
Explanation

(b)
$Cl_{2} + 2l^{-} \rightarrow I_{2} + 2Cl^{-}$
Rate of formation of
$I_{2} = \frac{dI_{2}}{dt} = - \frac{1}{2}\frac{dI^{-}}{dt}$
$= \frac{1}{2} \times \frac{0.20 - 0.18}{20}$
$= \frac{1}{2} \times \frac{0.02}{20}$
$= 5 \times 10^{- 4}mol\ L^{- 1}\min^{- 1}$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.