Q&A Hero

Q: Which of the following statements concerning entropy is/are true? 1) On a per mole basis, the solid form of a particular substance has a greater entropy than its gaseous form. 2) On a per mole basis at a fixed temperature, larger gaseous molecules tend to have a greater entropy than smaller gaseous molecules because of a greater number of comformations over which to disperse energy. 3) On a per mole basis, the liquid form of a particular substance has a greater entropy than the solid form of the substance. A) 1 only B) 2 only C) 3 only D) 2 and 3 E) 1, 2, and 3

Q: Which of the following statements concerning entropy change is/are true? 1) For a spontaneous process, . 2) For a spontaneous process, . 3) For an equilibrium process (such as a phase change), . A) 1 only B) 2 only C) 3 only D) 2 and 3 E) 1, 2, and 3

Q: Under what conditions does q, the heat evolved or absorbed by the system in a physical or chemical process, equal the change in enthalpy of the system?1) When q0.2) When w= 0.3) When w= -PV.A) 1 onlyB) 2 onlyC) 3 onlyD) 2 and 3E) 1, 2, and 3

Q: In which of the following scenarios is no change in the internal energy of the system possible?A) q< 0, w> 0B) q> 0, w> 0C) q= 0, w> 0D) q< 0, w= 0E) q< 0, w< 0

Q: A system under constant external pressure undergoes an increase in volume. What is the effect on the surroundings? A) Energy is transferred as pressure-volume work done on the surroundings. B) Energy is transferred as pressure-volume work done by the surroundings on the system. C) Energy is transferred as heat from the system to the surroundings. D) Energy is transferred as heat from the surroundings to the system. E) None of the above.

Q: What is the change in internal energy (U) of the system if q=-55 kJ and w= 58 kJ for a certain process?A) 3 kJB) -113 kJC) 113 kJD) -3 kJE) -55 kJ

Q: What is the change in internal energy of the system (U) if 36 kJ of heat energy is absorbed by the system and 84 kJ of work is done by the system for a certain process?A) -48 kJB) 120 kJC) 36 kJD) 48 kJE) -120 kJ

Q: For a particular process, q= 20 kJ and w= 15 kJ. Which of the following statements is true?A) U= 35 kJ.B) The system does work on the surroundings.C) Heat flows from the system to the surroundings.D) All of the above are true.E) None of the above are true.

Q: A gas absorbs 0.0 J of heat and then performs 77.0J of work. What is the change in internal energy of the gas?A) -77.0 JB) 37.0 JC) 117.0 JD) 76.6 JE) none of these

Q: H and U are nearly the same in all the following processes exceptA) F2(g) + H2(g) → 2HF(g).B) CH4(g) + Cl2(g) → CH3Cl(g) + HCl(g).C) C6H6(s) → C6H6(l).D) CuO(s) + H2(g) → Cu(s) + H2O(g).E) 3O2(g) → 2O3(g).

Q: For the isothermal (constant-temperature) expansion of an ideal gas, A) w> 0 and q< 0. B) w= 0 and q> 0. C) w< 0 and q= 0. D) w< 0 and q> 0. E) w> 0 and q> 0.

Q: According to the first law of thermodynamics, the energy of the universe is constant. Does this mean that E is always equal to zero?A) No, E does not always equal zero, but this is due only to factors such as friction and heat.B) No, E never equals zero because energy is always flowing between the system and the surroundings.C) No, E does not always equal zero because it refers to the system's internal energy, which is affected by heat and work.D) Yes, E= 0 at all times, which is why q= -w.E) No, E never equals zero because work is always being done on the system or by the system.

Q: Which of the following is not a state function?A) wB) HC) PD) UE) T

Q: Consider the following reaction:2C(s) + 3H2(g) → C2H6(g); Hº= -84.68 kJ; Sº= -173.8 J/K at 298KWhat is the equilibrium constant at 400.0K for this reaction?A) 1.0 x10-2B) 2.0 x104C) 1.0D) 9.5 x101E) 8.6 x10-10

Q: For the reaction G700K= -13.457kJ. What is Kp for this reaction at 700.K?A) 1.00B) 1.54C) 10.1D) 2.31E) none of these

Q: Which of the following statements is true concerning the reaction below?C(s, graphite)→C(s, diamond)SubstanceHºf(kJ/mol) at 298 KSº(J/(mol·K)) at 298 KC(s, graphite)05.740C(s, diamond)1.8972.377A) Under standard-state conditions, the reaction is spontaneous at all temperatures.B) Under standard-state conditions, the reaction is spontaneous only at temperatures above 564 K.C) Under standard-state conditions, the reaction is spontaneous only at temperatures below 564 K.D) Under standard-state conditions, the reaction is at equilibrium at 298 K.E) Under standard-state conditions, the reaction is not spontaneous at any temperature.

Q: Consider the following reaction, which is spontaneous at room temperature.C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g)One would predict thatA) H is positive and S is positive for the reaction.B) G is positive at all temperatures.C) H is negative and S is negative for the reaction.D) H is positive and S is negative for the reaction.E) H is negative and S is positive for the reaction.

Q: Condensation is a process for whichA) G is negative at high temperature but positive at low temperature.B) H, S, and G are positive at all temperatures.C) G is positive when condensation occurs spontaneously.D) H and S are positive at all temperatures.E) H and S are negative at all temperatures.

Q: Sublimation is an example of a process for whichA) H is positive and S is negative at all temperatures.B) H is negative and S is positive at all temperatures.C) H,S, and G are negative at all temperatures.D) H and S are positive at all temperatures.E) H, S, and G are positive at all temperatures.

Q: The reaction C(s) + CO2(g) → 2CO(g) is spontaneous only at temperatures in excess of 1100K. We can conclude thatA) G is negative for all temperatures.B) H is negative and S is negative.C) H is positive and S is positive.D) H is negative and S is positive.E) H is positive and S is negative.

Q: Which of the following statements is true for the following reaction?NH4HS(s) → NH3(g) + H2S(g); Hº= 93kJA) The reaction is not spontaneous at any temperature.B) The reaction is spontaneous only at relatively high temperatures.C) The reaction is at equilibrium under standard-state conditions.D) The reaction is spontaneous at all temperatures.E) The reaction is spontaneous only at relatively low temperatures.

Q: Which of the following statements is true concerning the reaction below?CH4(g) + N2(g) → HCN(g) + NH3(g); Hº= 164.1kJ; Gº= 159.1kJ at 298KA) It is nonspontaneous at all temperatures.B) It is spontaneous at relatively low temperatures only.C) It is spontaneous at all temperatures.D) It is at equilibrium at 298 K.E) It is spontaneous at relatively high temperatures only.

Q: Consider the following reaction, which is spontaneous at room temperature.NH3(g) + BF3(g) → H3NBF3(s)One would predict thatA) G is negative at all temperatures.B) H is positive and S is negative for the reaction.C) H is negative and S is positive for the reaction.D) H is positive and S is positive for the reaction.E) H is negative and S is negative for the reaction.

Q: Under standard-state conditions, a reaction with Hº<0 and Sº>0 isA) not spontaneous at low temperatures but spontaneous at high temperatures.B) at equilibrium.C) spontaneous at any temperature.D) spontaneous at low temperatures but not at high temperatures.E) not spontaneous at any temperature.

Q: For the reaction SrSO3(s) → SrO(s) + SO2(g), which is spontaneous only at high temperatures, one would predict thatA) H is negative and S is negative at room temperature.B) H is positive and S is positive at room temperature.C) H is positive and S is negative at room temperature.D) G is positive at high temperatures.E) H is negative and S is positive at room temperature.

Q: For the reaction CaCO3(s) → CaO(s) + O2(g) at 1atm pressure, the values of H and S are both positive, and the process is spontaneous at high temperatures. Which of the following statements about this reaction is true?A) The change in entropy is the driving force for the reaction.B) The process is exothermic at high temperatures and endothermic at room temperature.C) The reverse reaction is endothermic.D) The reverse reaction is nonspontaneous at room temperature.E) Gat room temperature is negative.

Q: The reaction CaO(s) + SO3(g) → CaSO4(s) is nonspontaneous at 2200K, whereas it is spontaneous at room temperature. Which of the following statements is false?A) The change in enthalpy is the main driving force of the reaction.B) Both H and S are negative for the reaction.C) G is negative at room temperature.D) The change in entropy is the main driving force of the reaction.E) G becomes zero at a temperature between 300 and 2200 K.

Q: A certain reaction has negative values for both H and S. Therefore, the reactionA) can be spontaneous if the temperature is low enough.B) cannot be spontaneous at any temperature.C) must be spontaneous at all temperatures.D) can be spontaneous if the temperature is high enough.E) has a positive free energy at any temperature.

Q: The reaction Br2(g) → 2Br(g) is spontaneous only at temperatures in excess of 1600ºC. We can conclude thatA) H is + and S is + for the reaction.B) H is - and S is + for the reaction.C) G is + for all temperatures.D) H is - and S is - for the reaction.E) H is + and S is - for the reaction.

Q: The following reaction is spontaneous at all temperatures:CaC2(s) + 2H2O(l) → Ca(OH)2(s) + C2H2(g)Which of the following statements is true?A) H is negative and S is positive.B) H is negative and S is negative.C) H is positive and S is negative.D) H is positive and S is positive.E) G is positive at all temperatures.

Q: For the reaction 4Ag(s) + O2(g) → 2Ag2O(s), Hº= -61.14 kJ and Sº=-132J/K at 25ºC. Which of the following statements is true? Assume that Hº and Sº are essentially temperature independent.A) The change in entropy is the driving force at low temperatures.B) The reaction will be spontaneous at high temperatures, and the reverse reaction will be spontaneous at low temperatures.C) The reaction will not be spontaneous at any temperature.D) The reaction will be spontaneous at low temperatures, and the reverse reaction will be spontaneous at high temperatures.E) The reaction will be spontaneous at all temperatures.

Q: For the reaction 2SO2(g) + O2(g) →2SO3(g), Hº and Sº are both negative at 298K, and the process is spontaneous at 298 K. Which of the following statements must also be true?A) The change in entropy is the driving force of the reaction.B) G is positive for the reaction at 298 K.C) The direction of the reaction may be reversed at high temperatures.D) Gis temperature independent.E) At high temperature, H becomes positive.

Q: What is Gº at 500.0 K for the following reaction?Sr(s) + H2O(g) → SrO(s) + H2(g) SubstanceHºf(kJ/mol) at 298 KSº(J/(mol·K)) at 298 KSr(s)052.3H2O(g)-241.8188.7SrO(s)-634.954.4H2(g)0130.6A) 365.1 kJB) -365.1 kJC) 376.4 kJD) -376.4 kJE) -421.1 kJ

Q: What is Gº at 298 K for the following equilibrium?Ag+(aq) + 2NH3(aq) Ag(NH3)2+(aq); Kf= 1.7 x107 at 298KA) -41 kJB) 41 kJC) -18 kJD) 0E) 18 kJ

Q: A 0.0228 Msolution of a particular weak base, B, has a pH of 9.11 at 298K. What is Gº for the following equilibrium?B(aq) + H2O(l) BH+(aq) + OH-(aq)A) 27.9 kJB) 51.9 kJC) 9.36 kJD) 46.4 kJE) 94.5 kJ

Q: A 0.0997 Msolution of a particular monoprotic weak acid, HA, has a pH of 6.00 at 298K. What is Gº for the following equilibrium?HA(aq) + H2O(l) H3O+(aq) + A-(aq)A) 28.5 kJB) 34.2 kJC) 620 kJD) 5.71 kJE) 62.7 kJ

Q: Consider the following reaction:2AgCl(s) → 2Ag(s) + Cl2(g); Hº= 127.1 kJ; Sº= 115.7 J/K at 298 KSuppose 41.0 g of silver(I) chloride is placed in a 70.0L vessel at 298K. What is the equilibrium partial pressure of chlorine gas? (R= 0.0821 L atm/(K·mol) = 8.31 J/(K·mol))A) 0.050 atmB) 5.1 x10-23atmC) 0.95 atmD) 0.10 atmE) 5.7 x10-17atm

Q: Water gas, a commercial fuel, is made by the reaction of hot coke carbon with steam:When equilibrium is established at 805ºC, the concentrations of CO, H2, and H2O are 4.00x10-2, 4.00x10-2, and 1.00x10-2mol/L, respectively. Calculate the value of Gº for this reaction at 805ºC.A) 53.7 kJB) 12.3 kJC) 16.4 kJD) -12.4 kJE) none of these

Q: Consider the following reaction:3C(s) + 3H2(g) → C3H6(g); Hº= 20.41 kJ; Sº= -131.6 J/K at 298 KWhat is the equilibrium constant at 298 K for this reaction?A) 3.5 x10-11B) 1.0C) 1.3 x10-7D) 2.8 x1010E) 2.6 x10-4

Q: Consider the following hypothetical reaction (at 316.8 K). Standard free energies, in kJ/mol, are given in parentheses. A B + C Gº = ? (-32.2) (207.8) (-237.0)What is the value of the equilibrium constant for the reaction at 316.8 K?A) 0.42B) 1.0C) 273D) 6.5 x104E) 0.32

Q: The standard free energy of formation of nitric oxide, NO, at 1000.K (roughly the temperature in an automobile engine during ignition) is 78.0kJ/mol. Calculate the equilibrium constant for the reaction2NO(g)at 1000. K. (R= 8.31 J/(K·mol))A) 0.95B) 7.0 x10-9C) 1.6 x105D) -15E) 8.4 x10-5

Q: A certain reaction is found to be product favored. Which of the following is a correct description of the reaction?A) Gº< 0, K> 1B) Gº> 0, K< 1C) Gº> 0, K> 1D) Gº< 0, K< 1E) Gº= 0, K> 1

Q: For a reaction that has an equilibrium constant of 7x10-3, which of the following statements must be true?A) S is positive.B) G is positive.C) G is negative.D) H is negative.E) H is positive.

Q: For a reaction, if Gº= 0, thenA) S= 0.B) K= 0.C) H= 0.D) K= 1.E) G= 0.

Q: Given the following, determine Kat 298K for the reaction,AgBr(s) → Ag+(aq) +Br-(aq)SubstanceGºf(kJ/mol) at 298 KBr(aq)-104.0Ag+(aq)77.12AgBr(s)-96.9A) B) C) D) E)

Q: Based on the following data, what is the standard Gibbs free energy of formation of the sulfate ion at 298K? (R= 8.31 J/(K·mol))CaSO4(s) Ca2+(aq) + SO42-(aq); Ksp= 2.4 x10-5 SubstanceGºf(kJ/mol) at 298 KCa2+(aq)-553.5CaSO4(s)-1322.0A) -768.5 kJ/molB) -1849.2 kJ/molC) -1875.5 kJ/molD) -742.2 kJ/molE) 794.8 kJ/mol

Q: What is the change in free energy at 298 K when 12.0 mL of 0.344 Mcalcium chloride is combined with 73.7 mL of 0.245 M sodium carbonate? (R= 8.31 J/(K·mol))Ca2+(aq) + CO32-(aq) → CaCO3(s) SubstanceGºf(kJ/mol) at 298 KCa2+(aq)-553.5CO32-(aq)-527.9CaCO3(s)-1128.8A) -36.0 kJB) -2.20 x103kJC) -41.3 kJD) -47.4 kJE) 9.16 x103kJ

Q: Consider the following reaction:CaO(s) + CO2(g) → CaCO3(s); Gº= -130.9 kJ at 298 KAt what partial pressure of CO2(g) will the reaction no longer be spontaneous at 298K? (R= 0.0821 L·atm/(K·mol) = 8.31 J/(K·mol))A) 1.59 x108atmB) 1.00 atmC) 6.28 x10-9atmD) 8.77 x1022atmE) 1.14 x10-23atm

Q: Which of the following is true for the reaction NH3(l) NH3(g) at -33ºC and 1 atm pressure? (The normal boiling point for NH3is -33ºC.)A) H= TSB) H= 0C) H= nRTD) S= 0E) H= PV

Q: For a certain process, at 300. K, Gº = -44.0 kJ and Hº=-7.0kJ. If the process is carried out reversibly, what is the amount of useful work that can be performed?A) -7.0 kJB) -51.0 kJC) -37.0 kJD) 37.0 kJE) -44.0 kJ

Q: An ideal fuel for the control jet of a space vehicle should decompose withA) G= 0 and H= 0.B) G< 0 and H< 0.C) G> 0 and H> 0.D) G< 0 and H> 0.E) G> 0 and H< 0.

Q: For a reaction system that is at equilibrium, which of the following must always be true?A) H= 0B) S= 0C) G= 0D) q= 0E) U= 0

Q: For a reversible phase change at constant temperature and pressure,A) G= 0.B) U= 0.C) w= 0.D) H= 0.E) q= 0.

Q: If a process is both endothermic and spontaneous, thenA) H= 0.B) G> 0.C) S> 0.D) U< 0.E) H< 0.

Q: Which of the following is correct for the condensation of gaseous methane at -166ºC? The normal boiling point of methane is -161ºC.A) H< 0, S> 0, and G> 0.B) H< 0, S< 0, and G< 0.C) H> 0, S< 0, and G< 0.D) H= 0, S= 0, and G< 0.E) H> 0, S> 0, and G> 0.

Q: Determine Gº for the following reaction:CH4(g) + 2O2(g) CO2(g) + 2H2O(l) SubstanceGºf(kJ/mol)CH4(g)-50.72O2(g)0CO2(g)-394.4H2O(l)-237.4A) -581.1 kJB) -818.5 kJC) 131.1 kJD) -682.5 kJE) -919.9 kJ

Q: Consider the following hypothetical reaction at 310K. Standard free energies of formation are given in parentheses. B C Gº = -20.7 kJ/mol (?) (176.4 kJ/mol)Calculate the standard free energy of formation of compound B.A) 155.7 kJ/molB) -197.1 kJ/molC) -155.7 kJ/molD) 197.1 kJ/molE) none of these

Q: Given the following, determine Gº at 298 K for the precipitation reaction,Ag+(aq) +Cl-(aq) → AgCl(s) SubstanceGf(kJ/mol) at 298 KCl-(aq)-131.3Ag+(aq)77.12AgCl(s)-109.8A) -55.6 kJ/molB) -164.0 kJ/molC) 55.6 kJ/molD) 164.0 kJ/molE) 98.6 kJ/mol

Q: Given the following, determine Gºf at 298 K for SnO.Sn(s) + SnO2(s) → 2SnO(s) ; Gº= 12.0 kJ at 298KSubstanceGºf(kJ/mol) at 298 KSnO(s)?SnO2(s)-515.8A) -251.9 kJ/molB) -503.8 kJ/molC) 527.8 kJ/molD) 263.9 kJ/molE) 1055.6 kJ/mol

Q: For which of the following substances is the standard free energy of formation not equal to zero at 298K?A) Ne(g)B) Gd(s)C) O2(g)D) Be(g)E) Cu(s)

Q: Which of the following has a value of zero for the standard free energy of formation at 298K? A) I(l) B) I2(g) C) I2(l) D) I2(s) E) I(g)

Q: What is Sº at 298 K for the following reaction?CH4(g) + N2(g) → HCN(g) + NH3(g); Hº= 164.1 kJ; Gº= 159.1 kJ at 298 KA) 2.0 J/KB) 5.5 x102J/KC) 1.1 x103J/KD) 5.3 x102J/KE) 17 J/K

Q: From these two reactions at 298 K,V2O3(s) + 3CO(g) → 2V(s) + 3CO2(g); Hº= 369.8 kJ; Sº= 8.3 J/KV2O5(s) + 2CO(g) → V2O3(s) + 2CO2(g); Hº= -234.2 kJ; Sº= 0.2 J/Kcalculate Gº for the following at 298 K:2V(s) + 5CO2(g) → V2O5(s) + 5CO(g)A) +133.1 kJB) +601.6 kJC) -601.6 kJD) -133.1 kJE) +1.6 kJ

Q: What is Gº at 298 K for the following reaction?I2(g) + Br2(g) → 2IBr(g); Hº= -11.6 kJ; Sº= 12 J/K at 298 KA) -8.02 kJB) 15.2 kJC) -15.2 kJD) 3.59 x103kJE) -3.59 x103kJ

Q: Which of the following is the best criterion for determining the spontaneity of a chemical reaction?A) HB) HC) GD) GE) TS

Q: What is the thermodynamic quantity that provides the criterion for the spontaneity of a chemical reaction?A) TSB) UC) SD) GE) H

Q: The free-energy change of a reaction is a measure of A) the excess entropy given off to the reaction system. B) the increased molecular disorder that occurs in the system. C) the energy given off to the surroundings. D) the direction in which a net reaction occurs. E) the excess entropy given off to the surroundings.

Q: Which of the following equations is correct?A) G= S- THB) G= H- PVC) G= H- TSD) G= Ginitial- GfinalE) G = S- PV

Q: What is the change in entropy when 5.46 mL of liquid benzene (C6H6, d=0.879g/mL) is combusted in the presence of 27.3 L of oxygen gas, measured at 298K and 1atm pressure? (R=0.0821L·atm/(K·mol))2C6H6(l) + 15O2(g) → 12CO2(g) + 6H2O(l); Sº= -437.7 J/K at 298 KA) -488 J/KB) -46.0 J/KC) -26.9 J/KD) -13.4 J/KE) -515 J/K

Q: What is the change in entropy when 0.646 g of water decomposes to form hydrogen gas and oxygen gas at 298K?2H2O(l) → 2H2(g) + O2(g); Sº= 326.3 J/K at 298 KA) 5.85 J/KB) 0.0785 J/KC) 23.4 J/KD) 11.7 J/KE) 211 J/K

Q: What is the change in entropy when 0.100 g of silicon is burned in excess oxygen to yield silicon dioxide at 298K?Si(s) + O2(g) → SiO2(s); Sº= -182.4 J/K at 298 KA) -182 J/KB) -18.2 J/KC) -2.18 x10-3J/KD) -5.12 x104J/KE) -0.649 J/K

Q: Given the following, determine Sat 298 K for one mole of NO(g).2NO(g) + O2(g) → 2NO2(g); Sº= -146.7 J/K at 298KSubstanceS(J/(mol K)) at 298 KNO(g)?O2(g)205.1NO2(g)240.0A) 210.9 J/KB) -90.85 J/KC) 421.7 J/KD) -421.7 J/KE) +90.85 J/K

Q: For the reaction N2(g) → 2N(g),A) H< 0 and S< 0.B) H> 0 and S< 0.C) H< 0 and S> 0.D) H= 0 and S> 0.E) H> 0 and S> 0.

Q: For the process Cl2(g) → 2Cl(g),A) H is + and S is + for the reaction.B) H is + and S = 0 for the reaction.C) H is - and S is - for the reaction.D) H is - and S is + for the reaction.E) H is + and S is - for the reaction.

Q: Which of the following reactions has the largest positive value of Sº per mole of O2 at 25ºC?A) 2H2(g) + O2(g) → 2H2O(g)B) 2C(s) + O2(g) → 2CO(g)C) 2Mg(s) + O2(g) → 2MgO(s)D) C(s) + O2(g) → CO2(g)E) 2NO(g) + O2(g) → 2NO2(g)

Q: For which of the following reactions is Sº>0 at 25C?A) MgO(s) + CO2(g) → MgCO3(s)B) 2H2(g) + O2(l) → 2H2O(l)C) 2Li(s) + O2(g) → Li2O(s)D) 2CO(g) + O2(g) → 2CO2(g)E) F3BNH3(s) → BF3(g) + NH3(g)

Q: Arrange the following reactions in order of increasing Sº value.1) H2(g) + F2(g) → 2HF(g)2) NH4NO3(s) → N2O(g) + 2H2O(l)3) (NH4)2Cr2O7(s) → Cr2O3(s) + 4H2O(l) + N2(g)A) 1 < 2 < 3B) 2 < 3 < 1C) 3 < 1 < 2D) 1 < 3 < 2E) 2 < 1 < 3

Q: For which of the following reactions is Sº< 0 at 25ºC?A) 2KClO3(s) → 2KCl(s) + 3O2(g)B) 2HgO(s) → 2Hg(l) + O2(g)C) Br2(l) → Br2(g)D) P4(s) + 5O2(g) → P4O10(s)E) (NH4)2Cr2O7(s) → N2(g) + 4H2O(l) + Cr2O3(s)

Q: Which of the following reactions has the smallest value of Sº at 25ºC?A) C6H6(l) + 9/2O2(g) → 6CO(g) + 3H2O(g)B) C6H6(s) → C6H6(l)C) C6H6(l) + Br2(l) → C6H5Br(l) + HBr(g)D) C6H6(s) → C6H6(g)E) C6H6(l) + 15/2O2(g) → 6CO2(g) + 3H2O(g)

Q: For which of the following reactions is Sº> 0 at 25ºC?A) 2H2(g) + O2(g) → 2H2O(g)B) 2ClBr(g) → Cl2(g) + Br2(g)C) I2(g) → I2(s)D) 2NO(g) + O2(g) → 2NO2(g)E) NH4HS(s) → NH3(g) + H2S(g)