Question

Methyl iodide decomposes according to the equation 2CH3I (g) => C2H6 (g) + I2 (g). Knowing that the reaction is governed by kinetics of order one and that its rate constant k = 1.5 × 10 ^ -4s at 300K. Calculate: a) the half life of the reaction b) the time during which the methyl iodide will be decomposed to 80%. c) the fraction of methyl iodide which will remain after 15 seconds if the initial concentration is 3.5 g / l.

Answer 1

So half life of a reaction is the time required for a reactant to reach one-half its initial concentration or pressure.

(a) To find a half life of the first order:

Use this equation: