CH Practice Exam #1

Size: px

Start display at page:

Download "CH Practice Exam #1"

Penelope Weaver
5 years ago
Views:

1 CH Practice Exam #1 Multiple Choice - Choose the best answer and place the letter corresponding to the answer in the space provided. 1. Determine the density of an object that has a mass of g and displaces 12.1 ml of water when placed in a graduated cylinder. A) 8.08 g/ml B) 1.38 g/ml C) 12.4 g/ml D) 18.1 g/ml E) 11.4 g/ml 2. What answer should be reported, with the correct number of significant figures, for the following calculation? ( ) / A) 4.6 B) 4.57 C) D) E) A student weighed µg of sulfur in the lab. This is the same mass as A) g. B) kg. C) mg. D) ng. 4. Calculate the mass (in kg) of 4.87 x 1025 atoms of Zn. A) 5.29 kg B) 1.89 kg C) 8.09 kg D) 1.24 kg E) 1.09 kg 5. Determine the name for TiCO3. Remember that titanium forms several ions. A) titanium (II) carbonate B) titanium carbide C) titanium carbonite D) titanium (II) carbonite E) titanium (I) carbonate

2 6. Determine the empirical formula for a compound that is 36.86% N and 63.14% O by mass. A) NO B) N2O C) NO2 D) N2O3 E) NO3 7. Write a balanced equation to show the reaction of gaseous ethane with gaseous oxygen to form carbon monoxide gas and water vapor. A) 2 C2H6(g) + 7 O2(g) 4 CO2(g) + 6 H2O(g) B) C2H6(g) + 5 O(g) 2 CO(g) + 3 H2O(g) C) 2 C2H6(g) + 5 O2(g) 4 CO(g) + 6 H2O(g) D) C2H6(g) + 7 O(g) 2 CO2(g) + 3 H2O(g) E) 2 CH3(g) + 5 O(g) 2 CO(g) + 3 H2O(g) 8. The chemical formula for calcium nitride is A) Ca(NO3)2. B) Ca(NO2)2. C) Ca3N2. D) CaN2. 9. How many moles are there in 3.00 g of ethanol, CH3CH2OH? A) mol B) mol C) 15.3 mol D) 138 mol 10. What mass of NO2 is contained in a 13.0 L tank at 4.58 atm and 385 K? A) 18.8 g B) 53.1 g C) 24.4 g D) 86.7 g E) 69.2 g.11. A gas occupies 4.23 L at 2.25 atm. What is the volume at 3.46 atm? A) 6.50 L B) 1.84 L C) 2.75 L D) 32.9 L E) L

3 12. A mixture of N2, O2 and He have mole fractions of 0.25, 0.65, and 0.10, respectively. What is the pressure of N2 if the total pressure of the mixture is 3.9 atm? A) 2.5 atm B) 0.39 atm C) 0.67 atm D) 0.98 atm E) 1.33 atm 13. Give the major attractive force acting between solvent and solute in salt water. A) dipole-dipole B) dispersion C) hydrogen bonding D) ion-ion E) ion-dipole 14. Choose the situation below that would result in a ΔHsolution near 0. A) When ΔHsolvent >> ΔHsolute B) When ΔHsolute > ΔHhydration C) When ΔHsolute < ΔHhydration D) When ΔHsolute is close to ΔHhydration E) There isn't enough information to determine. 15. Which of the following statements is generally TRUE? A) The solubility of a solid is not dependent on either temperature or pressure. B) The solubility of a solid is highly dependent on pressure. C) The solubility of a solid is highly dependent on both pressure and temperature. D) The solubility of a solid is highly dependent on temperature. E) None of the above. 16. Calculate the mass of oxygen (in mg) dissolved in a 5.00 L bucket of water exposed to a pressure of 1.13 atm of air. Assume the mole fraction of oxygen in air to be 0.21 and the Henry's law constant for oxygen in water at this temperature to be M/atm. A) 49.4 mg B) 23.5 mg C) 9.87 mg D) 27.3 mg E) 13.7 mg Cgas = khpgas

4 17. How many moles of KF are contained in 244 ml of m KF solution? The density of the solution is 1.22 g/ml. A) mol KF B) mol KF C) mol KF D) mol KF E) mol KF 18. Calculate the freezing point of a solution of g of ethylene glycol (C2H6O2) dissolved in g of water. Kf = 1.86 C/m and Kb = C/m. A) 8.32 C B) C C) 70.2 C D) 30.0 C E) C 19. Identify the solute with the lowest van't Hoff factor. A) any nonelectrolyte B) KI C) MgSO4 D) CaCl2 E) AlCl3 20. Choose the aqueous solution with the highest vapor pressure. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable. A) 0.50 m C4H10O4 B) 0.50 m C2H6O2 C) 0.50 m C5H12O5 D) 0.50 m C11H24O11 E) They all have about the same vapor pressure. 21. What is the mole fraction of I2 in a solution made by dissolving 55.6 g of I2 in 245 g of hexane, C6H14? A) B) C) D) 0.154

5 22. Choose the solvent below that would show the smallest boiling point elevation when used to make a 0.10 m nonelectrolyte solution. A) carbon tetrachloride, Kb = 5.03 C/m B) benzene, Kb = 2.53 C/m C) diethyl ether, Kb = 2.02 C/m D) acetic acid, Kb = 3.07 C/m E) water, Kb = C/m 23. Choose the aqueous solution below with the lowest freezing point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable. A) m LiCl B) m (NH4)3PO4 C) m NaBrO4 D) m KCN E) m KNO2 24. Give the electron geometry (eg), molecular geometry (mg), and hybridization for CH4. A) eg=tetrahedral, mg=trigonal planar, sp2 B) eg=trigonal pyramidal, mg=trigonal pyramidal, sp3 C) eg=tetrahedral, mg=tetrahedral, sp3 D) eg=trigonal pyramidal, mg=tetrahedral, sp3 E) eg=trigonal planar, mg=trigonal planar, sp2 25. Give the electron geometry (eg), molecular geometry (mg), and hybridization for NH3. A) eg=tetrahedral, mg=trigonal planar, sp2 B) eg=trigonal pyramidal, mg=trigonal pyramidal, sp3 C) eg=tetrahedral, mg=trigonal pyramidal, sp3 D) eg=trigonal pyramidal, mg=tetrahedral, sp3 E) eg=trigonal planar, mg=trigonal planar, sp2 26. Give the electron geometry (eg), molecular geometry (mg), and hybridization for the carbons in ethylene, CH2=CH2. A) eg=tetrahedral, mg=trigonal planar, sp2 B) eg=trigonal pyramidal, mg=trigonal pyramidal, sp3 C) eg=tetrahedral, mg=trigonal pyramidal, sp3 D) eg=trigonal pyramidal, mg=tetrahedral, sp3 E) eg=trigonal planar, mg=trigonal planar, sp2

6 27. Name the following compound: A) 4-methyl-4-propylpentane B) 4,4-dimethylheptane C) nonane D) 4-propyl-4-methylpentane E) 2-methyl-2-propylpentane 28. Name the following compound. A) 4-propyl-5-hexyne B) 2-methyl-4-pentyne C) 1-nonyne D) 4-methyl-3-propyl-1-pentyne E) 3-isopropyl-1-hexyne! 29. Write the balanced chemical equation for the catalytic hydrogenation (addition of H2) to CH3C CH. A) CH3C CH + H2 CH3CH=CH2 B) CH3C CH + 2 H2 CH3CH=CH2 C) CH3C CH + H2 CH3CH2CH3 D) CH3C CH + 2 H2 CH3CH2CH3 E) CH3C CH + H2 CH2=C=CH2 30. Which one of the following molecules is the least polar and most volatile? A) butane B) butanoic acid C) hexane D) ethanol 31. Identify a carboxylic acid. A) CH3CH2SCH2CH3 B) CH3CH2Br C) CH3CH2NH2 D) CH3COOH 32. Give the direction of the reaction, if K << 1.. A) The forward reaction is favored. B) The reverse reaction is favored. C) Neither direction is favored. D) If the temperature is raised, then the forward reaction is favored. E) If the temperature is raised, then the reverse reaction is favored.

7 33. The equilibrium constant is given for one of the reactions below. Determine the value of the missing equilibrium constant. H2(g) + Br2(g) 2 HBr(g) Kc = HBr(g) H2(g) + Br2(g) Kc =? A) B) C) D) E) What is Δn for the following equation in relating Kc to Kp? SO3(g) + NO(g) SO2(g) + NO2(g) A) 0 B) -1 C) -2 D) 2 E) Determine the value of Kc for the following reaction if the equilibrium concentrations are as follows: [N2]eq = 1.5 M, [H2]eq = 1.1 M, [NH3]eq = 0.47 M. N2(g) + 3 H2(g) 2 NH3(g) A) 3.5 B) 0.28 C) 9.1 D) 0.11 E) Which of the following statements is TRUE? A) If Q < K, it means the reverse reaction will proceed to form more reactants. B) If Q > K, it means the forward reaction will proceed to form more products. C) If Q = K, it means the reaction is at equilibrium. D) All of the above are true. E) None of the above are true Consider the following reaction at equilibrium. What effect will adding more SO3 have on the system? SO2(g) + NO2(g) SO3(g) + NO(g) A) The reaction will shift in the direction of products. B) The reaction will shift to decrease pressure. C) The reaction will shift in the direction of reactants. D) No change will occur.

1021_4th Exam_

1021_4th Exam_1030115 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Place the following substances in order of increasing vapor pressure at a