Question

The reaction H2(g)+F2(g)?2HF(g) is spontaneous at all temperatures. A classmate calculates the entropy change for this reaction and obtains a large negative value for ?S?.
Part A

Did your classmate make a mistake in the calculation?

Did your classmate make a mistake in the calculation?

There is mistake in the calculation. The second law states that in any spontaneous process there is an increase in the entropy of the universe.
There is mistake in the calculation. The second law states that in any spontaneous process the increase in the entropy of the system equals zero. Also there is a decrease in entropy of the system, as in the present case, this decrease is canceled by an increase in entropy of the surroundings.
There is no mistake in the calculation. The second law states that in any spontaneous process there is an decrease in the entropy of the system. Also there is a decrease in entropy of the system, as in the present case.
There is no mistake in the calculation. The second law states that in any spontaneous process the decrease in the entropy of the system equals zero. Also there might be a decrease in entropy of the system, as in the present case, this decrease is canceled by an increase in entropy of the surroundings.

Answer 1

Answer:

The correct answer is there is a mistake in the calculation. The second law of thermodynamics state that in any spontaneous process there is an increase in the entropy of the universe.

Explanation:

According to the second law a reaction will occur in a system spontaneously if the total entropy of both system and surrounding increases during the reaction.That means in case of spontaneous reaction entropy change is always positive.

     But according to the question the reaction H2+F2=2HF is spontaneous in all temperature.So according to the second law of thermodynamics i can say that my classmate made a mistake in calculation that"s why his result for entropy change comes negative.