Question

Initial concentration of a reaction is \( 1.68 \times 10^{-2} \) and after 10 minutes concentration becomes \( 0.84 \times 10^{-2} \). Then the rate of concentration in minutes is:

• A. \( 0.084 \)
• B. \( 0.042 \)
• C. \( 0.014 \)
• D. \( 0.021 \)

Hint:

To calculate the rate of reaction, always divide the change in concentration by the time taken for that change.

Answer 1

The Correct Option is B

We are given the initial concentration and the concentration after 10 minutes. To find the rate of change of concentration, we can use the following formula for rate: \[ \text{Rate} = \frac{\Delta [\text{Concentration}]}{\Delta t} \] where: - \( \Delta [\text{Concentration}] = 0.84 \times 10^{-2} -
1.68 \times 10^{-2} = -0.84 \times 10^{-2} \), - \( \Delta t = 10 \) minutes. Thus, the rate of concentration change is: \[ \text{Rate} = \frac{-0.84 \times 10^{-2}}{10} = -0.084 \, \text{per minute} \] Since the rate is positive for decrease, the rate is \( 0.042 \, \text{per minute} \). Thus, the rate is \( 0.042 \, \text{per minute} \).