Practice Exam A

1 Practice Exam 1A 1) Iron pentacarbonyl (Fe(CO) 5 ) reacts with phosphorous trifluoride (PF 3 ) and hydrogen, releasing carbon monoxide: Fe(CO) 5 + 2PF 3 + H 2 ? Fe(CO) 2 (PF 3 ) 2 (H) 2 + 3CO The reaction of 5.0 mol of Fe(CO) 5 , 8.0 mol of PF 3 and 6.0 mol of H 2 will release __________ mol of CO. A) 15 B) 5.0 C) 24 D) 6.0 E) 12 2) If you pour 300 mL of 0.10 M KOH into a beaker that contains 100 mL of 0.20 M HCl, the resulting solution will be A) 0.20 M with respect to KCl B) 0.10 M with respect to KCl C) 0.01 M with respect to HCl D) 0.04 M with respect to KOH E) 0.025 M with respect to KOH 3) Which species below is the nitride ion? A) Na + B) NO 3- C) NO 2- D) NH 4+ E) N 3- 4) Which of the following are strong electrolytes? a) HCl b) HC 2 H 3 O 2 c) NH 3 d) KCl A) a, d B) a, c, d C) a, b, c, d D) a, b, d E) b, d 5. Bromine is the only nonmetal that is a liquid at room temperature. Consider the isotope bromine-81. Select the combination which lists the correct atomic number, number of neutrons, and mass number, respectively. A) 35, 46, 81 B) 35, 81, 46 C) 81, 46, 35 D) 46, 81, 35 E) 46, 35, 81 2 6) Vanadium has two naturally occurring isotopes, 50 V with an atomic mass of 49.9472 amu and 51 V with an atomic mass of 50.9440. The atomic weight of vanadium is 50.9415. The percent abundances of the vanadium isotopes are __________% 50 V and __________% 51 V. A) 0.2500, 99.750 B) 99.750, 0.2500 C) 49.00, 51.00 D) 1.000, 99.000 E) 99.000, 1.000 7) In which species does sulfur have the highest oxidation number? A) S 8 (elemental form of sulfur) B) H 2 S C) SO 2 D) H 2 SO 3 E) K 2 SO 4 8) In the following reaction, what is oxidized? Zn(s) + CuSO 4 (aq) --> ZnSO 4 (aq) + Cu(s) A) Zn B) Cu 2+ C) SO 4 2- D) Cu E) Zn 2+ 9) Phosphoric acid and barium hydroxide react to produce barium phosphate 2H 3 PO 4 (aq) + 3Ba(OH) 2 (aq) ? Ba 3 (PO 4 ) 2 (s) + 6H 2 O(l) Assuming complete reaction, how many moles of barium phosphate are produced when 35.0 mL of 0.029 M H 3 PO 4 are added to 90.0 mL of 0.010 M Ba(OH) 2 ? A) 1.0x10 -4 mol B) 3.0x10 -4 mol C) 5.0x10 -4 mol D) 7.0x10 -4 mol E) 9.0x10 -4 mol 10) The net ionic equation for the reaction between aqueous solutions of HF and KOH is A) HF + KOH ? H 2 O + K + + F - B) HF + OH - ? H 2 O + F - C) HF + K + + OH - ? H 2 O + KF D) H + + OH - ? H 2 O E) H + + F - + K + + OH - ? H 2 O + K + + F 3 11) Calcium carbide, CaC 2 , (FW = 64 g/mol) reacts with water (FW = 18 g/mol) to produce acetylene, C 2 H 2 , (FW = 26 g/mol): CaC 2 (s) + 2H 2 O(g) --> Ca(OH) 2 (s) + C 2 H 2 (g) Production of 13 g of C 2 H 2 requires consumption of ________ g of H 2 O A) 4.5 B) 9.0 C) 18 D) 4.8x10 2 E) 4.8x10 -2 12) 3.337 g/cm 3 = __________ kg/m 3 A) 3.337 x 10 -9 B) 3.337 x 10 -5 C) 3337 D) 0.3337 E) 333.7 13) Which one of the following combinations of names and formulas of ions is incorrect? A) O 2 - oxide B) Al 3+ aluminum C) NO 3 - nitrate D) PO 4 3- phosphate E) CrO 4 2- chromate 14) Terephthalic acid, used in the production of polyester fibers and films, is composed of carbon, hydrogen, and oxygen. When 0.6943 g of terephthalic acid was subjected to combustion analysis it produced 1.471 g CO 2 and 0.226 g H 2 O. What is its empirical formula? A) C 2 H 3 O 4 B) C 3 H 4 O 2 C) C 4 H 3 O 2 D) C 5 H 12 O 4 E) C 4 H 7 O 15) Select the precipitate that forms when aqueous ammonium sulfide reacts with aqueous copper(II) nitrate A) CuS B) Cu 2 S C) NH 4 NO 3 D) NH 4 (NO 3 ) 2 E) NH 4 NO 2 4 16) Aluminum reacts with oxygen to produce aluminum oxide which can be used as an adsorbent, desiccant or catalyst for organic reactions. 4Al(s) + 3O 2 (g) ? 2Al 2 O 3 (s) A mixture of 82.49 g of aluminum (M = 26.98 g/mol) and 117.65 g of oxygen (M = 32.00 g/mol) is allowed to react. Identify the limiting reactant and determine the mass of the excess reactant present in the vessel when the reaction is complete. A) oxygen is the limiting reactant; 19.81 g of aluminum remain B) oxygen is the limiting reactant; 35.16 g of aluminum remain C) aluminum is the limiting reactant; 16.70 g of oxygen remain D) aluminum is the limiting reactant; 44.24 g of oxygen remain E) aluminum is the limiting reactant; 22.12 g of oxygen remain 17) How much heat is absorbed by a 75.0 g sample of gold at 25 o C when it is immersed in boiling water, assuming water remains at the boiling temperature. The specific heat of gold is 0.128 J/(K g) and the specific heat of water is 4.184 J/(K g) [A] 0.960 kJ [B] 0.720 kJ [C] 3.00 kJ [D] 4.18 kJ [E] 0.240 kJ 18) The valve between the 2.00-L bulb, in which the gas pressure is 1.00 atm, and the 3.00-L bulb, in which the gas pressure is 1.50 atm, is opened. What is the final pressure in the two bulbs, the temperature being constant and the same in both bulbs? [A] 0.900 atm [B] 1.25 atm [C] 1.30 atm [D] 2.25 atm [E] 2.50 atm 19) At standard conditions, it was found that 1.50 L of a gas weighed 4.75 g. The gas is [A] HNF 2 [B] NH 3 [C] NO 2 [D] NF 3 [E] N 2 F 4 5 20) The following equation represents the complete combustion of ethane: 2C 2 H 6 (g) + 7O 2 (g) ??? 4CO 2 (g) + 6H 2 O(g) Assuming all reactants and products are at the same temperature and pressure, what is the maximum volume in liters of carbon dioxide that can be obtained from 50 L of C 2 H 6 and 250 L of oxygen? [A] 25 [B] 100 [C] 150 [D] 50 [E] 200 21) A sample of oxygen is collected over water at a total pressure of 675 mmHg at 29°C. The vapor pressure of water at 29°C is 30.0 mmHg. The partial pressure of the O 2 is [A] 0.831 atm. [B] 0.955 atm. [C] 0.849 atm. [D] 1.00 atm. [E] 0.791 atm. 22) A 125 g aluminum block at an initial temperature of 95°C is dropped into a styrofoam flask containing 150 mL of water at 20°C. What is the final temperature? Specific heat of aluminum is 0.901 J/(g K), specific heat of water is 4.18 J/(g K), density of liquid water is 1.0 g/cm 3 . (Assume the styrofoam flask has zero heat capacity.) [A] 31°C [B] 36°C [C] 44°C [D] 49°C [E] 55°C 23) From a consideration of the reaction 2NO(g) + O 2 (g) ??? 2NO 2 (g) ?H = ?114.1 kJ if 2.00 × 10 2 g of NO 2 were produced, then the amount of heat released (heat released = -q) should be [A] 114 kJ. [B] 314 kJ. [C] 496 kJ. [D] 124 kJ. [E] 248 kJ. 6 24) Consider the following specific heats of metals. Metal Specific Heat copper 0.385 J / (g C) cobalt 0.418 J / (g C) chromium 0.447 J / (g C) gold 0.129 J / (g C) silver 0.237 J / (g C) ?° ?° ?° ?° ?° 100-g samples of each of the metals at 95°C are added to 100 mL of water at 25°C. Which element will increase the temperature of the water the least? [A] silver [B] copper [C] chromium [D] gold [E] cobalt 25) The standard heat of formation of lead nitrate corresponds to the reaction [A] Pb 2+ (aq) + 2NO 3 - (aq) ??? Pb(NO 3 ) 2 (s). [B] Pb(OH) 2 (s) + 2HNO 3 (aq) ??? Pb(NO 3 ) 2 (aq) + 2H 2 O(l) [C] Pb(s) + N 2 (g) + 3O 2 (g) ??? Pb(NO 3 ) 2 (s). [D] Pb(g) + N 2 (g) + 3O 2 (g) ??? Pb(NO 3 ) 2 (g). [E] Pb 2+ (aq) + 2NO 3 - (aq) ??? Pb(NO 3 ) 2 (aq) Please make sure you know how to solve ALL textbook ?Practice Problems? and ?General Problems? from chapters 1-6. dotie Microsoft Word - Practice Exam 1A.doc