Which of the following statements are correct with respect to major product obta | TestHub

Passage / Comprehension

A substance ' X ' dissociates by two parallel reactions with different ' Arrhenius constants $(A_{1}$ and $A_{2})$ " and different "Activation energies" ( $E_{a_{1}}$ and $E_{a_{2}}$ ) as shown.

$X (g) \frac{A _{1} = 2 \times 1 0 ^{14} s ^{- 1}}{E _{a_{1}} = 12 K cal / mol} Y (g); X (g) \frac{A _{2} = 2 \times 1 0 ^{14} \times e ^{- 2} s ^{- 1}}{E _{a_{2}} = 9 K cal / mol} Z (g)$

[Given : $R = 2 Cal / mol - K$ ]

Which of the following statements are correct with respect to major product obtained in the above parallel decay:

Options:

Answer:

Solution:

For parallel reactions:

$\frac{k _{1}}{k _{2}} = \frac{A _{1}}{A _{2}} e^{- (E_{a 1} - E_{a 2}) / RT}$

Given:

$A_{2} = A_{1} e^{- 2}$ , $E_{a 1} - E_{a 2} = 3000 c a l m o l^{- 1}$

At 300 K:

$\frac{k _{1}}{k _{2}} = e^{2 - \frac{3000}{2 \times 300}} = e^{- 3} < 1$

So Z is the major product $\Rightarrow$ (A) False.

At 800 K:

$\frac{k _{1}}{k _{2}} = e^{2 - \frac{3000}{2 \times 800}} = e^{0.125} > 1$

So Y is the major product $\Rightarrow$ (B) False.

Correct Option: (D) None of the statements are correct

Chemistry - Chemical Kinetics Question with Solution | TestHub

Options:

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