Question

2NO(g) + Cl₂(g) →→→ 2NOCI(g)Experiment230.0125M0.0125M0.0250MInitial [NO]a) Write the rate law equation for the reaction.b) What is the overall order of the reaction?0.0255M0.0510N0.0255N

Answer 1

Answer:

$\begin{gathered} a)\text{ Rate = k }\times\text{ \lbrack NO\rbrack}^2\text{ }\times\text{ \lbrack Cl}_2] \\ b)\text{ Order = 3} \end{gathered}$

Explanation:

Here, we want to deduce the rate law for the reaction given

According to the data provided:

$Rate\text{ = k\lbrack NO\rbrack}^a[Cl_2]\placeholder{⬚}^b$

where the values in the square parentheses represent the concentrations and k represents the rate constant

Let us work with equations 1 and 3:

$\begin{gathered} 2.27\text{ }\times10^{-5}\text{ = k }\times\text{ 0.0125}^a\text{ }\times\text{ 0.0255}^b \\ 9.08\text{ }\times\text{ 10}^{-5}\text{ = k }\times\text{ 0.0250}^a\text{ }\times\text{ 0.0255}^b \end{gathered}$

Divide equation 3 by 1:

$\begin{gathered} 4\text{ = 2}^a \\ a\text{ = 2} \end{gathered}$

To get b, we can use equations 1 and 2:

$\begin{gathered} 2.27\text{ }\times\text{ 10}^{-5}\text{ = k }\times\text{ 0.0125}^a\text{ }\times\text{ 0.0255}^b \\ 4.55\text{ }\times\text{ 10}^{-5}\text{ = k }\times\text{ 0.0125}^a\text{ }\times\text{ 0.0510}^b \end{gathered}$

Divide equation 2 by 1, we have it that:

$\begin{gathered} 2\text{ = 2}^b \\ b\text{ = 1} \end{gathered}$

The rate law for the reaction is thus:

$Rate\text{ = k }\times\text{ \lbrack NO\rbrack}^2\text{ }\times\text{ \lbrack Cl}_2]$

b) The overall order is the sum of the powers

That would be 1 + 2 = 3