Question

Consider the following data for the given reaction
2$$\text{HI}_{(g)} $\rightarrow$ \text{H}_2{(g)}$$ + $$\text{I}_2{(g)}

The order of the reaction is __________.

Answer 1

Assuming the rate law:

$\text{Rate} = k[\text{HI}]^n$

Using any two of the given data points:

$\frac{3.0 \times 10^{-3}}{7.5 \times 10^{-4}} = \left(\frac{0.01}{0.005}\right)^n$

Solving, we find $n = 2$, so the reaction is second order.

Answer 2

Assuming the rate law:

$\text{Rate} = k[\text{HI}]^n$

Using any two of the given data points:

$\frac{3.0 \times 10^{-3}}{7.5 \times 10^{-4}} = \left(\frac{0.01}{0.005}\right)^n$

Solving, we find $n = 2$, so the reaction is second order.