LAQ : How is the Absolute zero obtained from Charles’ law?

Question

How is the Absolute zero obtained from Charles’ law?

Answer

From Charle’s law, we know that, at constant pressure, the volume of a given mass of gas increases or decreases by $\frac{\mathrm{t/}}{}$ part of its volume at 0^oC for every 1 degree rise or fall in temperature.

Suppose, the temperature of the same gas is decreased to -t^oC. So, its volume at that temperature,

V_t = V_o(1+t/273)

From the above equation, it is evident that if the temperature is reduced to -273^oC, V_t will be zero.

Based on this observation, a new scale of temperature was adopted with its zero at -273^oC. This scale is known as the absolute scale and the zero reading of this scale is known as absolute zero.