9. The standard enthalpy of vaporization of methanol is 35.2 kJ/mol at its normal boiling point, 64.6°C.  What is the standard change in entropy for the vaporization of methanol at its normal boiling point?

For water, H20, the heat of vaporization at its normal boiling point of 100 °C is 40.7 kJ/mol. The entropy change when 1.76 moles of H20 vapor condenses at 100 °C, 1 atm is J/K.

The enthalpy for a certain process is 146.4 kJ/mol and the entropy for the process is 463.6 J/K.  At what temperature (in K) will the process become spontaneous?

For silicon, Si, the heat of fusion at its normal melting point of 1410 °C is 46.4 kJ/mol. The entropy change when 2.12 moles of liquid Si freezes at 1410 °C, 1 atm is J/K.

Consider entropy and its role in determining if chemical and physical processes are spontaneous. For any process to be spontaneous, what must happen to the entropy of the universe during that process? Acetone will spontaneously vaporize when coming in contact with your skin even though acetone has a much higher boiling point. Explain how this occurs in light of your answer to part (a).

For a particular chemical reaction H = 6.8 kJ and S = –29 J/K. Under what temperature condition is the reaction spontaneous?

For the reaction 2 A(g) → A2(g), Q = -20.00 kJ for the formation of onemole of A2(g) at constant volume and a temperature of 25.00◦C. If we did thissame reaction at constant pressure, what would be the values of Q, W, ∆U,and ∆H for the formation of one mole of A2(g) at a temperature of 25.00◦C?

Which pure substance under standard conditions would have the highest entropy?   O2   HCl   CH3OH   S