The reaction CH3I + CH3S- -> CH3SCH3 + I- follows the rate law rate = k[CH3I][CH3S-]. Solution X contains 0.10 M CH3I and 0.10 M CH3S- and has initial rate r. Solution Y, at the same temperature and in the same solvent, contains 0.30 M CH3I and 0.05 M CH3S-. Its initial rate is

JEE Main levelSingle correct optionDifficulty 2 of 3o3067

The reaction $CH X_{3} I + CH X_{3} S X^{-} CH X_{3} SCH X_{3} + I X^{-}$ follows the rate law rate $= k [CH X_{3} I] [CH X_{3} S X^{-}]$ . Solution X contains $0.10 M$ $CH X_{3} I$ and $0.10 M$ $CH X_{3} S X^{-}$ and has initial rate $r$ . Solution Y, at the same temperature and in the same solvent, contains $0.30 M$ $CH X_{3} I$ and $0.05 M$ $CH X_{3} S X^{-}$ . Its initial rate is

Rate

= k [CH X_{3} I] [CH X_{3} S X^{-}]

, so the rate is proportional to the product of the two concentrations. For X the product is

0.10 \times 0.10 = 0.010

and for Y it is

0.30 \times 0.05 = 0.015

. The ratio is

0.015/0.010 = 1.5

, so the rate of Y is

1.5 r