Question :
51) For a chemical reaction at equilibrium, which of the : 1282449
51) For a chemical reaction at equilibrium, which of the following would always decrease the concentrations of the products?
A) Increase the temperature.
B) Decrease the temperature.
C) Decrease the pressure.
D) Decrease the concentration of a gaseous or aqueous reactant.
52) The following reaction is endothermic: CaCO3 (s) CaO (s) + CO2 (g). Which of the following will cause the reaction to shift towards making more carbon dioxide gas?
A) increasing the temperature of the reaction
B) decreasing the temperature of the reaction
C) increasing the pressure of the system
D) increasing the pressure and decreasing the temperature of the system
53) Consider the following chemical system at equilibrium.
Heat + 6 H2O (g) + 2 N2 (g) 4 NH3 (g) + 3O2 (g)
Which of the following stresses would shift the equilibrium to the left?
A) increasing the concentration of O2
B) increasing the reaction temperature
C) increasing the concentration of H2O
D) decreasing the concentration of NH3
54) Consider the following system at equilibrium:
N2 (g) + 3 H2 (g) 2 NH3 (g) + 92. 94 kJ
Which of the following changes will shift the equilibrium to the right?
1. Increasing the temperature2. Decreasing the temperature
3. Increasing the volume4. Decreasing the volume
5. Removing some NH36. Adding some NH3
7. Removing some N28. Adding some N2.
A) 1, 4, 6, 7
B) 2, 3, 5, 8
C) 1, 6, 8
D) 2, 4, 5, 8
55) Coal burning plants release sulfur dioxide, a toxic gas, into the atmosphere. Nitrogen monoxide is released into the atmosphere via industrial processes and the combustion engine. Sulfur dioxide can also be produced in the atmosphere by the reaction of sulfur trioxide and nitrogen monoxide according to the following equilibrium. reaction
SO3 (g) + NO (g) + Heat SO2 (g) + NO2 (g)
Which of the following stresses will not shift the equilibrium to the right?
A) decrease the reaction chamber volume (pressure increase)
B) temperature increase
C) [NO2] decrease
D) [NO] increase
56) Which of the following conditions would force the reaction to go to completion?
2 N2 (g) + 6 H2O (g) + heat 4 NH3 (g) + 3 O2 (g)
A) continual removal of N2 gas
B) decrease the pressure on the reaction vessel
C) continual addition of NH3 gas to the reaction mixture
D) increase reaction temperature
16.2 Short Answer
1) a) Draw an energy diagram for the following reaction, whose activation energy is 75 kJ/mol and whose overall energy for the reaction is exothermic. Be sure to label all parts of the graph, including potential energy of reactant/products, Ea and enthalpy of reaction. b) How does a catalyst speed up a reaction? Explain and illustrate it on your graph.
H2 (g) + I2 (g) –> 2 HI (g) + heat
2) A 0.20 mole sample of C and a 0.10 mole sample of B are placed in a reaction chamber. At equilibrium, 0.080 mole of A is present. What is the composition of the equilibrium mixture in terms of moles of each substance present.
4 C (g) + B (g) 2 A (g)
0
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