Chem Hw
Kennedi.R
HWChapter17.docxHW Chapter 17 Name:
Show all your work in the space provided, and clearly indicate your final answer. No credit will be given for answers only.
1. Calculate S for the reaction SO2(s) + NO2(g) SO3(g) + NO(g). [3 pts]
2. HI has a normal boiling point of –35.4C, and its Hvap is 21.16 kJ/mol. Calculate the molar entropy of
vaporization (Svap). Be sure to include the correct units with your answer. [3 pts]
3. Sodium carbonate can be made by heating sodium bicarbonate:
2NaHCO3(s) Na2CO3(s) + CO2(g) + H2O(g)
Given that H = 128.9 kJ/mol and G = 33.1 kJ/mol at 25C, above what minimum temperature (in oC) will
the reaction become spontaneous under standard state conditions? [3 pts]
4. Hydrogen peroxide (H2O2) decomposes according to the equation
H2O2( l) H2O( l) + 1/2O2(g).
Calculate Kp for this reaction at 25C. (H = –98.2 kJ/mol, S = 70.1 J/K·mol) [3 pts]
5. At 1500C the equilibrium constant for the reaction
Calculate G (in kJ/mol) for this reaction at 1500C. [3 pts]
6. For the reaction 3 C2H2( g) → C6H6( l) at 25°C, the standard enthalpy change is -631 kJ and the standard
entropy change is -430 J/K. Calculate the standard free energy change at 25°C. [3 pts]
For 7 and 8, select correct response (1 pt each)
7. Based on the information given for equations I and II, which statement is true?
I. H2O( l) → H2O( g) T = 25°C, vessel open to atmosphere with 50% relative humidity
II. H2O( s) → H2O( l) T = 25°C, P = 1 atm
(1) I and II are both spontaneous.
(2) I is spontaneous and II is nonspontaneous.
(3) I is nonspontaneous and II is spontaneous.
(4) I and II are both nonspontaneous.
8. When a reaction reaches equilibrium at constant temperature and pressure,
(1) Q = 1.
(2) Δ Go = 0.
(3) S is maximized.
(4) G is minimized.
(5) Q = 0
