# A 60.0 mL volume of a gas was found to have a pressure of 2.0 atm at 25°C. What will be the new volume if the pressure is changed to 0.50 atm at constant temperature?

May 10, 2016

The second volume will be 240 mL.

#### Explanation:

This is an example of Boyle's law, which states that the volume of a given amount of a gas kept at constant temperature varies inversely with the pressure. In other words, if the volume increases, the pressure decreases, and vice versa. The equation to use is ${P}_{1} {V}_{1} = {P}_{2} {V}_{2}$.

Given
${P}_{1} = \text{2.0 atm}$
${V}_{1} = \text{60.0 mL}$
${P}_{2} = \text{0.50 atm}$

Unknown
V_2=???"

Solution
Rearrange the equation to isolate ${V}_{2}$. Substitute the given values into the equation and solve.

${P}_{1} {V}_{1} = {P}_{2} {V}_{2}$

${V}_{2} = \frac{{P}_{1} {V}_{1}}{P} _ 2$

V_2=((2.0"atm"xx60.0"mL"))/(0.5"atm")="240 mL"