# A #3 L# container holds #12 # mol and #9 # mol of gasses A and B, respectively. Groups of three of molecules of gas B bind to two molecules of gas A and the reaction changes the temperature from #160^oK# to #240^oK#. How much does the pressure change?

##### 1 Answer

The difficult aspect of this problem is finding the value of

#### Explanation:

This is an application of the ideal gas law in which

So, the ideal gas law (in ratio form) becomes

Since we are not given the initial pressure, the best we can do is find the fractional change in pressure, that is the ratio

Filling in what we are given

To find

Rearranging:

The pressure will decrease to 64.3% of its initial value.