(N/A) Charles' Law states that for a fixed mass of a gas at constant pressure,the volume of the gas is directly proportional to its absolute temperature $(T)$.
Mathematical Formula:
According to the law,for each degree rise in temperature,the volume of a gas increases by $\frac{1}{273.15}$ of its volume at $0^{\circ} C$ $(V_{0})$.
$V_{t} = V_{0} (1 + \frac{t}{273.15})$
$V_{t} = V_{0} (\frac{273.15 + t}{273.15})$
Defining absolute temperature $T = 273.15 + t$,we get:
$V_{t} = V_{0} (\frac{T}{T_{0}})$
$\frac{V}{T} = \text{constant } (k)$
$V = kT$
Graph:
$A$ plot of volume $(V)$ versus temperature $(T)$ at constant pressure yields a straight line passing through the origin,confirming $V \propto T$.
Absolute Zero Temperature:
Absolute zero is the theoretical temperature at which the volume of a gas becomes zero. It is defined as $-273.15^{\circ} C$ or $0 \ K$. At this temperature,all molecular motion theoretically ceases.