Physical Chemistry MCQ with Answers

Physical Chemistry MCQ with Answers

191) The bond dissociation energies of methane and ethane are 360 kcal⁄mol and 620 kcal⁄mol respectively. The C−C bond energy in kcal⁄mol is:

Answer is:

80

192) For a spontaneos process, the values of free energy and entropy change are respectively:

Answer is:

Positive and negative

Explanation:

In a spontaneous process, entropy increases and free energy decreases.

193) Which one of the following has the maximum entropy of vapourisation?

Answer is:

Diethyl ether

194) The free energy change is negative when:

Answer is:

The system does electrical work on the surroundings

195) The heat liberated on complete combustion of 7.8 gm benzene is 327 kJ. The heat was measured at constant volume at 27^oC. Calculate the heat of combustion of benzene at constant pressure:

Answer is:

−3270 kJ⁄mol

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