The reaction CHCl 3 g + Cl 2 g → CCl 4 g is first order in CHCl 3 and 1 2 order in Cl 2 . Write the rate law and overall order of reaction.

Given, The reaction CHCl 3 g + Cl 2 g → CCl 4 g is first order in CHCl 3 and 1 2 order in Cl 2 . Rate law is an expression that relates the rate of the reaction to the molar concentration of the reactants as determined experimentally. Therefore, the rate law can be written as given below: Rate, v = k CHCl 3 1 Cl 2 1 2 = k CHCl 3 Cl 2 1 2 , where k is called rate constant. Order of a chemical reaction is the sum of the powers of the concentration terms in the experimentally determined rate equation for the reaction. Therefore, overall order of the reaction = 1 + 1 2 = 3 2 .

E M B I B E

Chemistry Standard 12>Chapter 6 - Chemical Kinetics>Try This

MEDIUM

12th Maharashtra Board

IMPORTANT

Earn 100

For the reaction,
${NO}_{2} (g) + CO (g) \to NO (g) + {CO}_{2} (g)$

the rate of reaction is experimentally found to be proportional to the square of the concentration of ${NO}_{2}$ and independent that of $CO$ . Write the rate law.

Important Questions on Chemical Kinetics

HARD

12th Maharashtra Board

IMPORTANT

Chemistry Standard 12>Chapter 6 - Chemical Kinetics>Use your brain Power

The rate of the reaction

2 A + B ⟶ 2 C + D

is

6 \times 10^{- 4} mol {dm}^{- 3} s^{- 1}

when

[A] = [B] = 0.3 mol dm^{- 3}

. If the reaction is of first order in

A

and zeroth order in

B

, what is the rate constant?

HARD

12th Maharashtra Board

IMPORTANT

Chemistry Standard 12>Chapter 6 - Chemical Kinetics>Try This

The reaction

{CHCl}_{3} (g) + {Cl}_{2} (g) \overset{}{\to} {CCl}_{4} (g)

is first order in

{CHCl}_{3}

and

\frac{1}{2}

order in

{Cl}_{2}

. Write the rate law and overall order of reaction.

HARD

12th Maharashtra Board

IMPORTANT

Chemistry Standard 12>Chapter 6 - Chemical Kinetics>Try This>Q i)

A complex reaction takes place in two steps as shown below:

(i) $NO (g) + O_{3} (g) \overset{}{\to} {NO}_{3} (g) + O (g)$

(ii) ${NO}_{3} (g) + O (g) \overset{}{\to} {NO}_{2} (g) + O_{2} (g)$

The predicted rate law is $rate = k [NO] [O_{3}]$ . Identify the rate determining step. Write the overall reaction. Which is the reaction intermediate? Why?

MEDIUM

12th Maharashtra Board

IMPORTANT

Chemistry Standard 12>Chapter 6 - Chemical Kinetics>Exercises>Q 1

The rate law for the reaction