The reaction N2(g) + 3 H2(g) → 2 NH3(g) is thermodynamically spontaneous at 298 K, but becomes    nonspontaneous at higher temperatures.  Which of the following is true at 298 K?   a) ΔG, ΔH, and ΔS are all positive.    d) ΔG and ΔS are negative, but ΔH is positive. b) ΔG, ΔH, and ΔS are all negative.     e) ΔG and ΔH are positive, but ΔS is negative. c) ΔG and ΔH are negative, but ΔS is positive.

2 ΔΗ for the vaporization of benzene is 31.0 kJ/mol, and the boiling point (at atm of pressure) is 80.1 °C. Use this information to calculate Δs for the vaporization of benzene.

For each of the following reactions, calculate ΔH∘rxn, ΔS∘rxn, and ΔG∘rxn at 25 ∘C. State whether or not the reaction is spontaneous. If the reaction is not spontaneous, would a change in temperature make it spontaneous? If so, should the temperature be raised or lowered from 25 ∘C?2CH4(g)→C2H6(g)+H2(g), Calculate ΔS∘rxn at 25 ∘C. 2NH3(g)→N2H4(g)+H2(g) Calculate ΔS∘rxn at 25 ∘C. N2(g)+O2(g)→2NO(g) Calculate ΔS∘rxn at 25 ∘C. 2KClO3(s)→2KCl(s)+3O2(g) Calculate ΔS∘rxn at 25 ∘C.

From the values of ΔH and ΔS calculate the minimum temperature at which each reaction will become spontaneous. Enter "None" if the reaction is not spontaneous at any temperature. ΔH = -389 kJ/mol,  ΔS = 27.8  J/K · mol

Consider the reaction shown in the diagram.       What is the sign of Δ?ΔS for this reaction? Δ?>0ΔS>0 Δ?=0ΔS=0 Δ?<0

∆Gº for the reaction, H2(g)+Br2(g)⇄2HBr(g), is -33.3 kJ. Which statement below is true?   To make this reaction go forward, 33.3 kJ must be added.   This reaction is non-spontaneous.   This reaction is spontaneous.   This reaction cannot be at equilibrium.

Consider the reaction below for the decomposition of carbon tetrachloride gas:  CCl4(g)    ------>     C(s)     +        2Cl2 (g)    ΔH = + 95.7 kJ;  ΔS = + 142.2 J/K  If the reaction above is not spontaneous at 25 oC, determine at what temperature (if any) the reaction becomes spontaneous.

For a given reaction, ΔH∘∘= +35.5 kJ/mol and ΔS∘∘= +83.6 J/(K∙∙ mol). In what temperature range is the reaction spontaneous? Assume that ΔH∘∘ and ΔS∘∘ do not vary with temperature.

From the values of ΔH and ΔS predict which of the following reactions would be spontaneous at 25°C. Calculate the minimum temperature at which each reaction will become spontaneous. Enter "None" if the reaction is not spontaneous at any temperature. ΔH = -75.8 kJ/mol,  ΔS = 126  J/K · mol

For a particular reaction, Δ?=−14.20 kJ and Δ?=−198.5 J/K. Calculate Δ? for this reaction at 298 K