Assertion:CH₄, CO₂ has value of Z (compressibility factor) less than one at 0ºC. Reason :Z < 1 is due to the attractive forces dominate among the molecules.

Assertion: 4 2 and CO CH has value of Z(compressibility factor) less than one at 0ºC. Thus, the correct option is (a). Reason :Z< 1 is due to the attractive forces dominate among the molecules Explanation: The compressibility factor (Z) is given by, PV Z RT For ideal gases, Z=1, as there is no kind of attractive/repulsive forces are present. But for real gases, Z>1 or Z<1 Van der Waal equation for real gases is given as- 2 2 ( )(V nb) nRT an P V In case of 4 2 and CO CH , attractive forces predominate that means correction factor, 2 2 an V can’t be neglected whereas correction factor,