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Question
The molar heat capacity of oxygen gas at STP is nearly 2.5 R. As the temperature is increased, it gradually increases and approaches 3.5 R. The most appropriate reason for this behaviour is that at high temperatures
Options
oxygen does not behave as an ideal gas
oxygen molecules dissociate in atoms
the molecules collide more frequently
molecular vibrations gradually become effective
Solution
molecular vibrations gradually become effective
Molar specific heat capacity has direct dependence on the degree of freedom of gas molecules. As temperature is increased, the gas molecules start vibrating about their mean position, leading to change (increase) in the degree of freedom and, hence, increasing molar heat capacity.
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