AP Chem Unit 6 Missed Questions AP Classrm

½ H2(g) + ½ I2(s) → HI(g) ∆H = 26 kJ/molrxn ½ H2(g) + ½ I2(g) → HI(g) ∆H = -5.0 kJ/molrxn Based on the information above, what is the enthalpy change for the sublimation of iodine, represented below? I2(s) → I2(g)

A) 15 kJ/molrxn B) 21 kJ/molrxn C) 31 kJ/molrxn D) 42 kJ/molrxn E) 62 kJ/molrxn

4 NH3(g) + 3 O2(g) → 2 N2(g) + 6 H2O(g) If the standard molar heats of formation of ammonia, NH3(g), and gaseous water, H2O(g), are -46 kJ/mol and -242 kJ/mol, respectively, what is the value of ΔH°298 for the reaction represented above?

A -190 kJ/molrxn B -290 kJ/molrxn C -580 kJ/molrxn D -1,270 kJ/molrxn E -1,640 kJ/molrxn

Q11 HCl(aq)+NaOH(aq)→NaCl(aq)+H2O(l)ΔH°=−57.1kJ/molrxn The chemical equation above represents the reaction between HCl(aq) and NaOH(aq). When equal volumes of 1.00MHCl(aq) and 1.00MNaOH(aq) are mixed, 57.1kJ of heat is released. If the experiment is repeated with 2.00MHCl(aq), how much heat would be released?

A 28.6kJ28.6kJ B 57.1kJ57.1kJ C 85.7kJ85.7kJ D 114kJ114kJ

CO(g) + 2 H2(g) ⇄ CH3OH(g) ; ΔH < 0 The synthesis of CH3OH(g) from CO(g) and H2(g) is represented by the equation above. The value of Kc for the reaction at 483 K is 14.5. Which of the following statements is true about bond energies in this reaction?

A The energy absorbed as the bonds in the reactants are broken is greater than the energy released as the bonds in the product are formed. B The energy released as the bonds in the reactants are broken is greater than the energy absorbed as the bonds in the product are formed. C The energy absorbed as the bonds in the reactants are broken is less than the energy released as the bonds in the product are formed. D The energy released as the bonds in the reactants are broken is less than the energy absorbed as the bonds in the product are formed.

2H2S(g)+3O2(g)→2H2O(l)+2SO2(g); ΔH°=−1120kJ/mol Based on the reaction represented by the chemical equation shown above, what is the amount of heat released when 4.00mol of H2S(g) reacts with 9.00mol of O2(g)?

A −560kJ B −1120kJ C −2240kJ D −3360kJ

NaOH(aq) + HCl(aq) → H2O(l) + NaCl(aq) A student is trying to determine the heat of reaction for the acid-base neutralization reaction represented above. The student uses 0.50 M NaOH and 0.50 M HCl solutions. Which of the following situations, by itself, would most likely result in the LEAST error in the calculated value of the heat of reaction?

A) The thermometer was incorrectly calibrated and read 0.5 Celsius degree too high during the procedure. B) The volume of the acid solution added to the calorimeter was actually 1.0 mL less than what was recorded. C) The calorimeter was poorly insulated, and some heat escaped to the atmosphere during the procedure. D) The actual molarity of the base solution was 0.53 M but was recorded as 0.50 M. E) The final temperature of the mixture was taken before the contents of the calorimeter had reached thermal equilibrium.

Based on the bond energies shown in the table, what reaction energy curve diagram represents the change in energy as the reaction represented below proceeds? H2(g)+ Cl2(g)→2HCl(g) H-H: 430 Cl-Cl: 240 H-Cl: 430

Exothermic; H2+Cl2 on product side with a 190 kJ increase, 2HCl on product side