2. Methanol can be synthesized by combining carbon monoxide and hydrogen. H rxn = 90.7 kj

Transcription

1 Chemistry 30 Final Review Question Carousel 1. Give the IUPAC name for the following compound: 1. ANSWER: B A. 4-ethenyl-5-ethyl-4-methyl-5-phenyldecane B. 4-ethyl-3-methyl-5-phenyl-3-propylnon-l-ene C. 4-ethyl-3-methyl-6-phenyl-3-propylnon-l-ene D. 4-ethyl-3-methyl-3-propyl-5-phenylnon-l-ene 2. Methanol can be synthesized by combining carbon monoxide and hydrogen. CO (g) + 2 H 2(g) CH 3 OH (g) H rxn = 90.7 kj A reaction vessel contains these compounds at equilibrium. What effect will be seen when equilibrium is re-established after decreasing the temperature by 45 C? A. The concentration of methanol will decrease. B. The concentration of methanol will increase. C. The total pressure will increase. D. The concentration of hydrogen will increase. 3. The oxidation number of nitrogen in the nitrite ion,, is: A. +1 B. +2 C. +3 D ANSWER: B 3. ANSWER: C

2 4. Ethane can be formed by reacting acetylene with hydrogen. C 2 H 2(g) + 2 H 2(g) C 2 H 6(g) H rxn = 311 kj Under which reaction conditions would you expect to have the greatest equilibrium yield of ethane? A. high temperature, high pressure B. low temperature, high pressure C. high temperature, low pressure D. low temperature, low pressure 4. ANSWER: B 5. A solution of 0.20 mol/l benzoic acid has a ph of 2.45, a poh of 11.55, and a K a of The percent ionization of the benzoic acid is: A. 1.4% B. 1.8% C. 6.3% D. 20% 5. ANSWER: B 6. Race car drivers prefer to use gasoline that is high in isooctane, 2,2,4-trimethylpentane. The quantity of this molecule in gasoline determines its octane rating. Sketch the structure of isooctane. 6. ANSWER: 7. If 44.7 kj of energy is transferred when 1.65 g of ethanol, CH 3 CHO(l), is burned in a calorimeter, then the molar enthalpy of combustion of ethanol is A kj/mol B X 10 1 kj/mol C X 10 1 kj/mol D X 10 3 kj/mol 7. ANSWER: D

3 8. All of the following can be used to increase the rate of a chemical reaction except A. adding a catalyst B. increasing the temperature C. decreasing the pressure of a gas D. increasing the surface area of a solid or liquid 9. Acid rain is linked to the leaching of heavy metals and their ions in lakes and rivers. Biomagnification of these metals and ions increases levels of disease in fish and wildlife. Based on this information, a decision to reduce sulphur dioxide emissions would be A. political B. scientific C. technological D. environmental 10. All of the following methods may be used to predict and explain changes in enthalpy except A. bond energies B. Hess law C. Calorimetry D. Titration 8. ANSWER: C 9. ANSWER: D 10. ANSWER: D 11. The addition of a catalyst is required for the conversion of 2- propanol to propene. An appropriate catalyst for this reaction is A. KMnO 4 B. H 2 SO 4 C. NaOH D. H An appropriate property to measure the reaction rate in the following reaction is: A. change in mass B. change in colour C. change in pressure D. change in temperature 11. ANSWER: B 12. ANSWER: C

4 13. ANSWER: The molar enthalpy of formation for cyclopropane, C 3 H 6(g) is kj/mol. 14. ANSWER: 14. Write the cathode, anode, and net cell reaction equation for the electrolysis of molten lithium bromide. 15. The enthalpy change for reaction 1,, can be obtained by combining the enthalpy changes for the other reactions in which of the following ways? A. B. C. D. 15. ANSWER: D 16. At a certain temperature the reaction has K c = If 2.00 mol of carbon dioxide and 1.50 mol of hydrogen are placed in a 5.00 L vessel and equilibrium is established, what will be the concentration of carbon monoxide? CO 2(g) + H 2(g) CO (g) + H 2 O (g) A mol/l B mol/l C mol/l D. 219 mol/l 16. ANSWER: C

5 17. Rank the following compounds from most to least thermochemically stable. 1. CO 2 (g) 2. NaCl(s) 3. C 2 H 2 (g) 4. O 2 (g) 17. ANSWER: How much energy is released in the production of 2.37 g of nitrogen dioxide according to the following equation? NO(g) O 2(g) NO 2 (g) 18. ANSWER: An interpretation that applies to the data in the table above is that the greater the number of carbon atoms in a fossil fuel molecule, the A. Lower the energy stored in the molecule B. Greater the strength of each covalent bond C. Greater the energy released during combustion D. Lower the moles of oxygen required for complete combustion 19. ANSWER: C 20. A piece of stainless steel with a mass of 1.60 g absorbs 141 J of energy when its temperature increases by 178 C. What is its specific heat capacity? 20. ANSWER: 0.495

6 ANSWER: The enthalpy of combustion, c H, for heptane, C 7 H 16 (l), is kj/mol. How much heat is released by the burning of 10.0 g of heptane? 22. ANSWER: The molar enthalpy of combustion of ethanol is kj/mol. How much water can be heated from 13.5 C to 24.7 C by the combustion of 22.0 g of ethanol? 23. ANSWER: In a container with a high temperature ethyne reacts completely with hydrogen. The initial concentrations of hydrogen and ethyne are both 2.7 mol/l. At equilibrium, the concentration of ethyne is 2.4 mol/l. Determine the equilibrium constant for this system. A B C D ANSWER: C 25. The molar enthalpy change for the combustion of butane gas? A kj/mol B kj/mol C kj/mol D kj/mol 25. ANSWER: A