2. In which case MUST a reaction be spontaneous, independent of T?
DH = 0, DS must be positive. DH = 0, DS is negative. DS = 0, DH is positive. DH is negative, DS is positive. None of these
3. If an endorthermic reaction is spontaneous at 298 K, which of the following must be true for the reaction?
DG is greater than zero DG is greater than zero DG and DH are greater than zero DH and DS are greater than zero DG, DH, DS are all greater than zero
4. The melting point of water is 0oC at 1 atm pressure because under these conditions:
DS for the process H2O(s)--> H2O(l) is positive. DS and DSsurr for the process H2O(s)--> H2O(l) are both positive. DS and DSsurr for the process H2O(s)--> H2O(l) are equal in magnitude and opposite in sign. DG is positive for the process H2O(s)--> H2O(l). None of these is correct.
5. Choose the CORRECT statement:
Exothermic reactions are always spontaneous Free energy is independent of temperature. A reaction which exhibits a negative value of D S cannot be spontaneous. At constant P and T, a decrease in free energy insures an increase in the entropy of the system. None of the above statements are true.
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