Question

The following data was recorded for the decomposition of XY compound at 750K

What is the order of reaction with respect to decomposition of XY?

• A. 0
• B. 2
• C. 1
• D. 1.5

Hint:

To determine the order of reaction, take the ratio of the rates of reaction at two different concentrations, then use logarithms to solve for the order. In this case, you get a second-order reaction.

Answer 1

The Correct Option is B

For the given data, we can use the rate law to determine the order of reaction: The rate law is: \[ \text{Rate} = k[\text{XY}]^n \] Where: - $\text{Rate}$ is the rate of decomposition of XY, - $[\text{XY}]$ is the concentration of XY, - $n$ is the order of the reaction, - $k$ is the rate constant. Taking the ratios of the rates for two different concentrations, we can find the order $n$: \[ \frac{\text{Rate}_2}{\text{Rate}_1} = \left(\frac{[\text{XY}]_2}{[\text{XY}]_1}\right)^n \] Using the first two points: \[ \frac{22.0 \times 10^{-7}}{5.5 \times 10^{-7}} = \left(\frac{0.8}{0.4}\right)^n \] Simplifying the equation: \[ 4 = (2)^n \] \[ n = 2 \]
Thus, the order of reaction is 2.