# At 7.0°C, the volume of a gas is 49 mL. At the same pressure, its volume is 74 mL at what temperature?

##### 1 Answer
Jun 7, 2016

We use Charles' Law to give ${T}_{2} \cong 423 \cdot K$

#### Explanation:

Chalres' law states that at constant pressure, $V \propto T$, i.e. ${V}_{1} / {T}_{1} = k$ or ${V}_{1} / {T}_{1} = {V}_{2} / {T}_{2}$, units of absolute temperature are (reasonably) used, and we could use any units of volume ($\text{pints, bushels, pecks?}$), because the volumes cancel out.

${T}_{2} = \frac{{T}_{1} {V}_{2}}{V} _ 1$ $=$ $\frac{280 \cdot K \times 74 \cdot m L}{49 \cdot m L}$ $=$ ??K =??""^@C