You visited us 3 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard XII

Chemistry

Types of Elementary Reactions

The substance...

Question

The substance undergoes first order decomposition. The decomposition follows two parallel first order reactions as given above.
If the corresponding activation energies of parallel reaction are 100 and 120 $k J m o l^{- 1}$ then the net activation energy of A is / are:

120 kJ mol

^{- 1}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

116 kJ mol

^{- 1}

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

100 kJ mol

^{- 1}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

150 kJ mol

^{- 1}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C 116 kJ mol $^{- 1}$
The expression for the net activation energy is $E = \frac{k_{1} E_{1} + k_{2} E_{2}}{k_{1} + k_{2}}$
Substitute values in the above expression.
$E = \frac{10^{- 2} \times 100 + 120 \times 4 \times 10^{- 2}}{10^{- 2} + 4 \times 10^{- 2}} = 116 k J m o l^{- 1}$

Suggest Corrections

Similar questions

Q. The rate constant for two parallel reactions were found to be

1.0 \times 10^{- 2} {dm}^{3} {mol}^{- 1} s^{- 1}

and

3.0 \times 10^{- 2} {dm}^{3} {mol}^{- 1} s^{- 1}

. If the corresponding energies of activation of the parallel reactions are

60.0 {kJ mol}^{- 1}

and

70.0 {kJ mol}^{- 1}

respectively, what is the apparent overall energy of activation?

Q. Consider the given reaction. The rate constant for two parallel reactions were found to be

\times 10^{- 2} {{d m}^{3} {m o l}^{- 1} s}^{- 1}

and

4 \times 10^{- 2} {{d m}^{3} {m o l}^{- 1} s}^{- 1}

. If the corresponding energies of activation of the parallel reaction are

100

and

120 k J / m o l

respectively, what is the net energy of activation (

E_{a}

) of

A

Q. The rate constant for two parallel reactions were found to be

1.0 \times 10^{- 2} d m^{3}

m o l^{- 1} s^{- 1}

and

3.0 \times 10^{- 2} d m^{3}

m o l^{- 1} s^{- 1}

. If the corresponding energies of activation of the parallel reactions are 60.0 KJ

m o l^{- 1}

and 70.0 KJ

m o l^{- 1}

respectively, then what is the apparent overall energy of activation?

Q. The recombination of methyl radicals has no activation barrier. The activation energy values for the first step in the thermal thermal decomposition of acetaldehyde given and

E_{p h o t o c h e m i c a l}

are

309.32 k J m o l^{- 1}

and

41.8 k J m o l^{- 1}

respectively.
Calculate the overall activation energy for the thermal decomposition of acetaldehyde.

For the reaction $A + B \to C + D Δ H = - 20 k J m o l^{- 1}$ . The activation energy of the forward reaction is $85 k J m o l^{- 1}$ . The activation energy for backward reaction is

Join BYJU'S Learning Program

The substance undergoes first order decomposition. The decomposition follows two parallel first order reactions as given above.If the corresponding activation energies of parallel reaction are 100 and 120 kJ mol−1 then the net activation energy of A is / are:

The correct option is C 116 kJ mol−1The expression for the net activation energy is E=k1E1+k2E2k1+k2Substitute values in the above expression.E=10−2×100+120×4×10−210−2+4×10−2=116 kJ mol−1

The substance undergoes first order decomposition. The decomposition follows two parallel first order reactions as given above.
If the corresponding activation energies of parallel reaction are 100 and 120 $k J m o l^{- 1}$ then the net activation energy of A is / are: