Download Reaction Spontaneity Questions

Chemistry 30
Mrs. K. Thompson
Name: __________________
Reaction Spontaneity Questions
1. Compare and contrast enthalpy and entropy.
2. If a system becomes more disordered during a process, how does the system’s
entropy change?
3. From each pair, pick the one with the greater entropy.
a. NH3 (g) and NH3 (l)
b. NH3 (g) and NH3 (aq)
c. CO2 (s) and CO2 (g)
d. KBr (s) and KBr (l)
4. Predict the sign (either +∆S or -∆S) for each of the following changes:
a. ClF (g) + F2 (g)  ClF3 (g)
b. NH3 (g)  NH3 (aq)
c. CH3OH (l)  CH3OH (aq)
d. C10H8 (l)  C10H8 (s)
e. 2H2(g) + O2 (g)  2H2O (g)
f. Dissolving a sugar cube in a cup of tea.
5. Solve for ∆G0system and determine if each of the following processes or reactions is
spontaneous or non-spontaneous.
a. ∆H0 system = -75.9 kJ, T = 273 K, ∆S0 system = 138 J/K
b. ∆H0 system = -27.6 kJ, T = 535 K, ∆S0 system = -55.2 J/K
c. ∆H0 system = 365 kJ, T = 388 K, ∆S0 system = -55.2 J/K