# The first order rate constant for hydrolysis of CH3Cl in H2O has a value of 3.32x10-10 s-1 at 25oC and 3.13x10-9 s-1 at 40oC. What is the activation energy?

##### 1 Answer

The activation energy for the hydrolysis of

Like the other answer suggested, you need to use the **Arrhenius equation** to determine the activation energy for this reaction.

This equation allows you easily calculate the activation energy when you have two values for the rate constant measured at two different temperatures. Let's take

and

Take the natural log on both sides for both of these equations, you'll get

**(1)** and **(2)**

We should find a way to remove **(2)** from equation **(1)**

You'll end up with

Now just plug in your values and solve for *do not forget to use temperature in Kelvin*