# A sample of gas occupies a volume of 70.9 mL. As it expands, it does 118.9 J of work on its surroundings at a constant pressure of 783 torr. What is the final volume of the gas?

##### 1 Answer

#### Explanation:

The relationship between work (

where,

since the gas is expanding, then the work is done by the system and it is of a **negative value** .

Note that work, in this case, should be expressed in

Since work is done by the system:

Pressure should then be expressed in

Thus, replacing every term in its value in the expression

Note that

Here is a video that further explains this topic:

**Thermochemistry | The Nature of Energy.**