# Help on Gas Laws (Combined Gas Law)?

## The volume of a gas filled balloon is 30.0 L at 40 degrees Celsius and 153 kPa pressure. What volume will the balloon have at standard temperature and pressure (STP)?

Well, $\frac{{P}_{1} {V}_{1}}{T} _ 1 = \frac{{P}_{2} {V}_{2}}{T} _ 2$.........
And so we solve for ${V}_{2}$...
${V}_{2} = \frac{{P}_{1} \times {V}_{1} \times {T}_{2}}{{P}_{2} \times {T}_{1}}$...and we fills in the blanks...
$= \frac{153 \cdot k P a \times 30.0 \cdot L \times 273.15 \cdot K}{100 \cdot k P a \times 313.15 \cdot K} = 40.0 \cdot L$