For the evaporation of water at 37oC, is the value of Q negative, zero, or positive?

Reword the statement in Question 109 so that it is always true. Criticize this statement: Provided it occurs at an appreciable rate, any chemical reaction for which rG 0 will proceed until all reactants have been converted toproducts.

Why is it usually easier to use G to determine the spontaneity of a process rather than Su ?

When ammonium chloride is added to water and stirred, it dissolves spontaneously and the resulting solution feels cold. Without doing any calculations, deduce the signs of G, H, and S for this process, and justify your choices.

Explain why the statement No process is 100 efficient is not the best statement of the second law of thermodynamics.

For a liquid, which would you expect to be larger, Sfusion or Sevaporation? Why?

Explain why absolute entropies can be measured.

Ethanol burns in air or oxygen according to the equation C2H5OH(l)+3O2(g)2CO2(g)+3H2O(g) Predict the sign of S for this reaction.

Given the following information at 25C, calculate G at 25C for the reaction 2A(g)+B(g)3C(g) Substance Hf(kJ/mol) S(J/molK) A(g) 191 244 B(g) 70.8 300 C(g) 197 164 a 956 kJ b 956 kJ c 346 kJ d 346 kJ e 1.03 103 kJ

If q for a process is a positive number, then the system is (gaining/losing) energy.