# A balloon contains 146.0 mL of gas confined temperature of 1.30 atm and a temperature of 5.0°C. If the pressure doubles and the temperature decreases to 2.0°C, what will be the volume of gas in the balloon?

May 1, 2017

We use the $\text{Combined Gas Law}$.........

#### Explanation:

We use the $\text{Combined Gas Law}$, which holds that $\frac{{P}_{1} {V}_{1}}{T} _ 1 = \frac{{P}_{2} {V}_{2}}{T} _ 2$.

And so...........

${V}_{2} = \frac{{P}_{1} {V}_{1}}{T} _ 1 \times {T}_{2} / {P}_{2} = \frac{1.3 \cdot a t m \times 146.0 \cdot m L}{278 \cdot K} \times \frac{275 \cdot K}{2.6 \cdot a t m}$

$\cong 70 \cdot m L$

That the volume has almost halved is reasonable in that the temperature has not changed very much, BUT the pressure HAS DOUBLED. Provided we use absolute temperatures, we are free to use non-standard units of litres, (or even pints), with these laws of proportionality.