H_2(g) + Cl_2(g) → 2HCl_(g) ...... rate = r₁
D_2(g) + Cl_2(g) → 2DCl_(g) ..... rate = r₂.
The value of r₁ > r₂. Then the correct statement among the following is

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

H - H and D - D bond lengths are same

The activation energy for the first reaction is greater than the second reaction

H - H has greater bond energy than D - D

The activation energy for the first reaction is less than the of the second reaction

answer is C.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

The order of bond dissociation energy (BDE):

\begin{array}{*{20}{c}} {D - D\; > \;H - H\;} \\ {\left[ {\;\;{D_{2\;}}\;\;\; > \;\;{H_2}\;\;\;\;} \right]} \end{array}

The order of bond lengths (B.L):

\begin{array}{*{20}{c}} {D - D\; \approx \;H - H\;} \\ {\left[ {\;\;{D_{2\;}}\;\;\; \approx \;\;{H_2}\;\;\;\;} \right]} \end{array}

→ The bond dissociation energy of heavier isotopes is greater than that of lighter isotopes.
→ As the bond dissociation energy increases the time required to break the bond in the reaction increases, therefore rate of reaction (r) decreases. i.e,. The reaction which involes heavier isotopes proceeds with slower rate (r₁) than the reaction which involes lighter isotopes(r₁)

\large {H_{{2_{(g)}}}}\; + \;C{l_{{2_{(g)}}}}\; \to \;2HC{l_{(g)}}\;\;\;{r_1}

\large {D_{{2_{(g)}}}}\; + \;C{l_{{2_{(g)}}}}\; \to \;2HC{l_{(g)}}\;\;\;{r_2}

(1) B.L : H-H ≈ D-D
→ Correct but it is not correct explaination for the rates of above reaction
(2) B.L (or) B.D.E: D-D > H-H
(3)

⇒ [Ea]₂> [Ea]₁ and

Activation Energy:(Ea)
The energy difference between the Activated complex and reactants is called Activation energy.
The reaction with high activation energy proceeds with slow rate

Watch 3-min video & get full concept clarity

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Books for IIT JEE

Best Books for NEET

How to Join IIT after 10th