The following rate data were obtained at 300 K for the reaction 2 A + B ⟶ C + D Experiment No. [ A ] molL - [ B ] molL - Rate of formation of D molL - min - 1. 0 . 1 0 . 1 5 . 0 × 10 - 3 2. 0 . 3 0 . 2 6 . 0 × 10 - 2 3. 0 . 3 0 . 4 2 . 4 × 10 - 1 4. 0 . 4 0 . 1 2 . 0 × 10 - 2 Calculate the rate of formation of D when: [ A ] = 0 . 5 mol L - 1 and [ B ] = 0 . 2 mol L - 1

Rate law for a chemical reaction is an expression that provides a relationship between the rate of the reaction and the concentrations of the reactants participating in it. The rate law can be expressed as, Rate = k [ A ] p [ B ] q On comparing the experiments 2 and 3 ( Rate ) 2 = k [ 0 . 3 ] p [ 0 . 2 ] q = 6 . 0 × 10 - 2 .......(i) ( Rate ) 3 = k [ 0 . 3 ] p [ 0 . 4 ] q = 2 . 4 × 10 - 1 ......(ii) Upon dividing equations (ii) and (i), we get [ 2 ] q = 4 or q = 2 On comparing experiments 4 and 1 ( Rate ) 4 = k [ 0 . 4 ] p [ 0 . 1 ] q = 2 . 0 × 10 - 2 .......(iii) ( Rate ) 1 = k [ 0 . 1 ] p [ 0 . 1 ] q = 5 . 0 × 10 - 3 ......(iv) Upon diving equations (iii) and (iv), we get [ 4 ] p = 4 or p = 1 Substitute the values of p and q in the equation (iv), the value of rate constant is calculated as, k [ 0 . 1 ] 1 [ 0 . 1 ] 2 = 5 . 0 × 10 - 3 k = 5 Rate of formation of D when [ A ] = 0 . 5 mol L - 1 and [ B ] = 0 . 2 mol L - 1 is calculated as, k [ A ] p [ B ] q = 5 × [ 0 . 5 ] 1 [ 0 . 2 ] 2 = 0 . 1 mol L - 1 min - 1 Rate = k [ A ] [ B ] 2 ; 0 . 1 mol L - min -

HARD

12th West Bengal Board

IMPORTANT

Earn 100

A first order reaction is $15 %$ complete in $20$ minutes. In what time will the reaction $60 %$ complete?

Important Questions on Chemical Kinetics

EASY

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 4 - Chemical Kinetics>Follow Up Problems>Q 15

The half-life of a first order reaction is $30 \min .$

Calculate the specific rate constant of the reaction.

HARD

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 4 - Chemical Kinetics>Follow Up Problems>Q 15

The half-life of a first order reaction is $30 \min .$

What fraction of the reactant remains after $70 \min ?$

HARD

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 4 - Chemical Kinetics>Follow Up Problems>Q 15

The half-life of a first order reaction is $30 \min .$

How long would be required for $25 %$ of the reactant to be decomposed?

HARD

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 4 - Chemical Kinetics>Follow Up Problems>Q 16

The reaction ${SO}_{2} {Cl}_{2} ⇌ {SO}_{2} + {Cl}_{2}$ is
a first order gas reaction with $t_{1 / 2} = 3.15 \times 10^{4} s$ at $320 ° C .$ What percentage of ${SO}_{2} {Cl}_{2}$ is decomposed on heating this gas for $90$ minutes?

[Hint. Find $\log \frac{a}{a - x} = 0.0516$ . Now find $x / a = 0.112$ . If $a = 100$ then $x = 100 \times 0.112 = 11.2 %]$

HARD

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 4 - Chemical Kinetics>Follow Up Problems>Q 17

Show that in case of a first order reaction, the time required for

99.9 %

of the reaction to take place is about ten times than that required for half the reaction.

HARD

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 4 - Chemical Kinetics>Follow Up Problems>Q 18

Half-life of a first order reaction at given temperature is

3

minutes. Calculate the time required for completion of

3 / 4 th

of the reaction.

HARD

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 4 - Chemical Kinetics>Follow Up Problems>Q 19

The following rate data were obtained at $300 K$ for the reaction $2 A + B ⟶ C + D$

Experiment No.	$[A]$ ${molL}^{-}$	$[B]$ ${molL}^{-}$	Rate of formation of $D {molL}^{-} \min^{-}$
1.	$0.1$	$0.1$	$5.0 \times 10^{- 3}$
2.	$0.3$	$0.2$	$6.0 \times 10^{- 2}$
3.	$0.3$	$0.4$	$2.4 \times 10^{- 1}$
4.	$0.4$	$0.1$	$2.0 \times 10^{- 2}$

Calculate the rate of formation of D when: $[A] = 0.5 mol L^{- 1}$ and $[B] = 0.2 mol L^{- 1}$

HARD

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 4 - Chemical Kinetics>Follow Up Problems>Q 20

The rate of reaction,

2 NO + {Cl}_{2} ⟶ 2 NOCl

is doubled when concentration of

{Cl}_{2}

is doubled and it becomes

8

times when concentrations of both

NO

and

{Cl}_{2}

are doubled. Deduce the order of this reaction.

A first order reaction is 15% complete in 20 minutes. In what time will the reaction 60% complete?

Important Questions on Chemical Kinetics

Learn and Prepare for any exam you want !

A first order reaction is $15 %$ complete in $20$ minutes. In what time will the reaction $60 %$ complete?