Question

Absolute zero (0K) is that temperature at which
$A.$ Matter ceases to exist
$B.$ Ice melts and water freezes
$C.$ Volume and pressure of a gas becomes zero
$D.$ None of the above

Answer 1

HINT- Absolute zero is the lowest limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reach their minimum value, taken as zero Kelvin.

Complete step-by-step answer:
The theoretical temperature is determined by extrapolating the ideal gas law; by international agreement absolute zero is taken as - $273.15{}^o$ on the Celsius scale. The corresponding Kelvin and Rankine temperatures scales set their zero points at absolute zero by definition. The most transparent definition of this standard comes from the Maxwell-Boltzman distribution. It can also be found in Fermi-Dirac statistics and Bose-Einstein statistics. All of these define the relative numbers of particles in a system as decreasing exponential functions of energy (at the particle level) over kT, with k representing the Boltzman constant and T representing the temperature at macroscopic level.
Now according to the question, Absolute zero is characterised by no atomic motion. Both Charles’ law and the pressure law lead to an extrapolation back to zero volume or pressure which would imply the pressure scale can go no further. For all gases, absolute zero is the same and although clearly the gas would no longer be a gas there, Therefore the correct option for the above question is $C.$ (volume and pressure of a gas becomes zero).

NOTE- So we learnt about the absolute zero Kelvin, it’s definition and implementation on the above question and found out that at absolute zero Kelvin the volume and pressure of a gas becomes zero. Absolute zero cannot be achieved, although it is possible to reach temperatures close to it through the use of cryocoolers, dilution refrigerators, and nuclear adiabatic demagnetization.