COMEDK 2025 Evening Shift | Chemical Kinetics Question 5 | Chemistry

During a chemical reaction $\mathrm{X} \rightarrow \mathrm{Y}$, the rates of reaction starting with initial concentrations of X as $4.0 \times 10^{-3} \mathrm{M}$ and $2.0 \times 10^{-3} \mathrm{M}$ are $4.8 \times 10^{-4} \mathrm{~mol} \mathrm{~L}^{-1} / \mathrm{s}$ and $1.2 \times 10^{-4} \mathrm{~mol} \mathrm{~L}^{-1} / \mathrm{s}$ respectively. What is the order of reaction with respect to X ?

1.5

COMEDK 2025 Afternoon Shift

MCQ (Single Correct Answer)

-0

The hydrogenation of Ethyne is carried out at 600 K . The same reaction when carried out in presence of a catalyst maintaining the same rate constant, the temperature required is only 400 K . If the catalyst lowers the Activation energy of the reaction by $20 \mathrm{~kJ} / \mathrm{mol}$, what is the value of $\mathrm{E}_{\mathrm{a}}$ ?

$60 \mathrm{~kJ} / \mathrm{mol}$

$100 \mathrm{~kJ} / \mathrm{mol}$

$50 \mathrm{~kJ} / \mathrm{mol}$

$80 \mathrm{~kJ} / \mathrm{mol}$

COMEDK 2025 Afternoon Shift

MCQ (Single Correct Answer)

-0

The time needed for completion of $80 \%$ is $y$ times the half-life period of a first order reaction. What is the value of $y$ ?

0.648

3.46

2.32

0.322

COMEDK 2025 Afternoon Shift

MCQ (Single Correct Answer)

-0

Which one of the following is incorrect?

Rate constant equals the rate of reaction when concentration of reactants equals unity.

Larger the value of rate constant $(\mathrm{k})$ value faster is the chemical reaction.

The unit for rate constant for $n^{\text {th }}$ order reaction is $\left(\mathrm{mol} \mathrm{L}^{-1}\right)^{n-1} \mathrm{~s}^{-1}$

The value of rate constant $(\mathrm{k})$ is independent of concentration of reactants.

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