2. Rubidium has a heat of vaporization of 69.0 kJ/mol at its boiling point (686oC). For the process Rb(l)-->Rb(g) at 1 atm and 686oC. Calculate the value of DSuniverse.
0 69.0 kJ/mol 71.9 J/K mol 61.0 kJ/mol -7.97 kJ/mol
3. 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.
4. Which of these statements is false?
For a spontaneous reaction DG is negative Independent of T, a reaction must be spontaneous if DH = 0 and DS is positive A spontaneous reaction is always fast A spontaneous reaction occurs without outside intervention None of the above is false
5. For the phase change of liquid to solid, DS is:
0 positive negative positive at high temperature none of the above
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