2. For the phase change of liquid to solid, DS is:
0 positive negative positive at high temperature none of the above
3. The 3rd Law of Thermodynamics States that:
Energy is artificial Energy can neither be created nor lost The entropy of the universe is decreasing The entropy is zero at zero K for a perfect crystal none of the above
4. 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
5. 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.
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