In terms of Charles' law explain why –273∘C is the lowest possible temperature.
Charles’ law states that at constant pressure, the volume of a fixed mass of gas is directly proportional to its absolute temperature.
It was found that for all gases (at any given pressure), the plots of volume vs. temperature (in ∘C) is a straight line. If this line is extended to zero volume, then it intersects the temperature-axis at –273∘C. In other words, the volume of any gas at –273∘C is zero.
This is because all gases get liquefied before reaching a temperature of –273∘C.
Hence, it can be concluded that –273∘C is the lowest possible temperature.