Question

Three experiments are running in separate vessels, following 1$^{st}$ order kinetics.
Experiment-(A) 100 ml, 10 M
Experiment-(B) 200 ml, 10 M
Experiment-(C) 100 ml, 10 M + 100 ml H$_2$O
Select correct order of rate of reaction in above experiments.

• A. A = B = C
• B. A>B>C
• C. A>B>C
• D. A>B = C

Hint:

In 1$^{st}$ order reactions, the rate is directly proportional to the concentration of the reactant, so a higher concentration results in a faster reaction.

Answer 1

The Correct Option is B

Step 1: Understanding rate of reaction for 1st order kinetics.
For a 1$^{st}$ order reaction, the rate of reaction is directly proportional to the concentration of reactant. Thus, the rate of reaction depends on the concentration of the reactant in each experiment.

Step 2: Analyzing the experiments.
- Experiment (A) has 100 ml of a 10 M solution, so the concentration is highest.
- Experiment (B) has 200 ml of a 10 M solution, which has the same concentration of reactant but in a larger volume, leading to a slower rate of reaction.
- Experiment (C) has 100 ml of a 10 M solution mixed with 100 ml of H$_2$O, diluting the concentration, leading to the slowest rate of reaction.

Step 3: Conclusion.
Thus, the rate of reaction follows the order: A>B>C. Hence, option (2) is the correct answer.