# Boyle Law help

1. Jan 14, 2004

### hecate

can anyone tell me the steps to do this problem?

You are given a gas that you measure under a pressure of 720 mmHg. When the pressure is changed to 760 mmHg, the volume becomes 580 mL. What was the original volume of the gas?

I don't know how to do this problem. thanx!

2. Jan 14, 2004

### Warr

Its this simple ratio:

$$\frac{P_{1}}{V_{1}} = \frac{P_{2}}{V_{2}}$$

so to find $$V_{1}$$

$$V_{1} = \frac {P_{1}V_{2}}{P_{2}}$$

Last edited: Jan 14, 2004