1 Which of the following reactions shows the greatest increase in entropy?A) SO3 (g) -----> 2 SO2 (g) + O2 (g) B) H2 O(l) ----> H2 O(s) C) Br2 (l) ----> Br2 (g) D) H2 O2 (l) ----> H2 O(l) + 1/2 O2 (g) 2 Without consulting entropy tables, predict the sign of D S for the following process and choose the correct reasoning for your prediction: N2 (g, 10 atm) ----> N2 (g, 1 atm). The mass of N2 remains constant.A) positive; there is an increase in the number of gas molecules. B) positive; the gas expands into a larger volume. C) negative; the gas is compressed into a smaller volume. D) negative; the gas expands into a larger volume. E) negative; there is a decrease in the number of gas molecules. 3 Which of the following reactions will have the most positive D Ho ?A) N2 (g) ----> 2 N(g) B) F2 (g) ----> 2 F(g) C) O2 (g) ----> 2 O(g) D) These reactions would all have the same D Ho . 4 Rubidium has a heat of vaporization of 69.0 kJ/mol and an entropy of vaporization of 71.9 J/K.mol. Calculate the boiling point of rubidium.A) 687 K B) 273 K C) 32 o F D) 687 o C 5 Calculate D So rxn for the following reaction:
4 Cr(s) + 3 O2 (g) ----> 2 Cr2 O3 (s).Substance D So , J/K·molCr(s) 23.77 O2 (g) 205.138 Cr2 O3 (s) 81.2
A) 548.1 J/K B) 147.7 J/K C) -147.7 J/K D) -548.1 J/K 6 For the process C6 H6 (l) ----> C6 H6 (s) at a temperature above the freezing point of C6 H6 ,A) D S is positive.B) D H is positive.C) D G is positive.D) D G = O.7 Keq = 7.0 at 35 o C for the reaction A + B ----> C + Calculate D Go for this reaction.A) - 4.98 kJ B) 2.46 kJ C) - 5.66 kJ D) 4983 kJ 8 Sodium carbonate can be prepared by heating sodium bicarbonate.
2 NaHCO3 (s)
----> Na2 CO3 (s) + CO2 (g) + H2 O(g).
Given that D Ho = 128.9 kJ and D So = 321 J/K·mol for this reaction, at what temperature will K = 1?A) 401.6 K B) 401.6 o C C) 33.1 K D) 33.1 9 Consider the reaction SO2 (g) + NO2 (g) ----> SO 3 (g) + NO(g), which occurs at 298 K. Given the information below, determine which of the following choices is correct.compound D Go , kJ/molSO2 (g) -300.4 SO3 (g) -370.4 NO(g) 86.7 NO2 51.8
A) K > 1; D G > 0 B) K > 1; D G < 0 C) K < 0; D G > 0 D) K < 0; D G < 0 10 In the following reaction, SO2 (g) + CuO(s) ----> Cu(s) + SO3 (g), sulfur dioxide _____ reduce copper(II) oxide at 298 K.substance D Ho f , (kJ/mol)So , J/K·mol SO2 (g) -296.2 248.5 CuO(s) -157.3 42.7 Cu(s) 0 33.5 SO3 (g) -395.4 256.1
A) will; D Go is positive. B) will; D Go is negative. C) will not; D Go is positive. D) will not; D Go is negative. E) will not; D Go = 0.