课程名称︰普通化学丙 课程性质︰必修 课程教师︰黄信炅 开课学院：工学院 开课系所︰工科海洋系 考试日期（年月日）︰2011/4/21 考试时限（分钟）：150分钟左右 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : 1. Naming the following compounds.(10 pts) (a) CsClO (b) KBrO4 (c) N2O (d) Mn(OH)2 (e) O2F2 (f) PCl5 (g) HCN (h) HC2H3O2 (i) GaCl3 2. Write formula fot the following compound.(10 pts) (a) cesium hydride (b) thallium(III) nitrate (c) chromium(III) chloride (d) lithium permanganate (e) ammonium nitrite (f) vanadium(V) oxide (g) calcium sulfite (h) cadmium phosphate (i) cobalt(II) bromide (j) copper(I) iodate 3. Give the balance equation for each of the following chemical reactions. (a) KO2(s) + H2O(l) --> KOH(aq) + O2(g) + H2O2(aq) (2 pts) (b) Combustion of 47.6 mg cumene produces some CO2 and 42.8 mg water. The molar mass of cumene is between 115 and 125 g/mol and cumene is a compound containing only carbon and hydrogen.(4 pts) (mass of C in 1 mol = 12.01 g, mass of H in 1 mole = 1.008 g, mass of O in 1 mole = 16.00 g) (c) MnO4-(aq) + Fe2+(aq) --> Mn2+(aq) + Fe3+(aq) (Acid) (2 pts) 4. A 10.00-mL sample of vinegar, an aqueous solution of acetic acid, is titrated with 0.5062M NaOH, and 16.58 mL is required to reach the equivalence point. (a) What is the molarity of the acetic acid? (3 pts) (b) If the density of the vinegar is 1.006 g/cm3, what is the mass percent of acetic acid in vinegar? (3 pts) (mass of C in mol = 12.01 g, mass of H in 1 mol = 1.008 g, mass of O in 1 mol = 16.00 g) 5. Dimethylnitrosamine, (CH3)2N2O, is a carcinogenic (canser-causing) substrate that may be formed in foods, beverages, or gastric juices from reaction of nitrite ion (used as a food preservative) with other substrate. (12 pts) (mass of N in 1 mol = 14.01 g; Avogadro's number = 6.022 * 10^23) (a) What is the molar mass of the dimethylnitrosamine? (b) How many moles of (CH3)2N2O molecules are present in 250 mg dimethylnitrosamine? (c) What is the mass of 0.050 mol dimethylnitrosamine? (d) How many atoms of hydrogen are in 1.0 mol dimethylnitrosamine? (e) What is the mass of 1.0 * 10^6 molecules of dimethylnitrosamine? (f) What is the mass in gram of one molecule of dimethylnitrosamine? 6. A steel cylinder contains equimolar of graphite (pure carbon) and O2. The mixture in ignite and all the graphite reacts. Combustion produces a mixture of CO gas and CO2 gas. After the cylinder has cooled to its original temperture, the pressure of the cylinder has increase by 20.0%. Calculate the mole fractions of CO, CO2, and O2 in final gaseous mixture (4 pts). 7. At elevated temperatures, sodium chlorate decomposed to produce sodium chloride and oxygen gas. A 0.8765-g sample of impure sodium chlorate was heated until the production of oxygen gas ceased. The oxygen gas colleced over water occupied 57.2 mL at a temperature of 22℃ and pressure of 734 torr. Calculate the mass percent of NaClO3 in original sample. (At 22℃ the vapor pressure of water is 19.8 torr.) (4 pts) (mass of Na in 1 mol = 22.99 g, mass of Cl in 1 mol = 35.45 g; 1 atm = 760. torr; R = 0.08206 L atm/K mol; 0℃ = 273K) 8. At 25℃, the following heats of reaction are known: △H(kJ/mol) 2ClF + O2 --> Cl2O + F2O 167.4 2ClF3 + 2O2 --> Cl2O + 3F2O 341.4 2F2 + O2 --> 2F2O -43.4 At the same temperture, calculate △H for the reaction: (4 pts) ClF + F2 --> ClF3 9. Use these reactions and standard enthalpies, △H0 (4 pts) 2 ZbO(s) + 1/2 O2(g) --> Zb2O3(s) -128.0 kJ ZbO(s) + 1/2 O2(g) --> ZbO2(s) -380.0 kJ 2 ZbO(s) + 3/2 O2(g) --> Zb2O5(s) -344.5 kJ To find the value for Zb2O3(s) + O2(g) --> Zb2O5(s) 10. Which of the following statement is/are true? (a) q(heat) is a state function because △H is a state function and q = △H. (b) When 50.0 g of aluminum at 20.0℃ is placed in 50.0 mL of water at 30.0 ℃, the H2O will undergo a smaller temperature change than the aluminum. (The density of H20 = 1.0 g/mL, specific heat capacity of H2O = 4.18 J/℃˙g, specific heat capacity of aluminum = 0.89 J/℃˙g) (c) When a gas is compressed, the work is negative since the surroundings is doing work on the system and energy flows out of the system. (d) For the reaction (at constant pressure) 2N2(g) + 5O2(g) --> 2N2O5(g), the change in enthalpy is the same whether the reaction takes place in one step or a series os steps. 11. A check of the formulas of the ethylene, water, and ethanol suggests that the reaction, C2H4(g) + H2O(g) --> C2H5OH(l) could be made to occur under the correct conditions. This is a wild idea, but Mike says it's just a matter of the right catalyst combination, reator temperature, and pressure. Using the values in the table below, what is the calculated value of △H0 for Mike's proposed reaction? (4 pts) C(s) + 2H2(g) --> CH4(g) △H0 = -74.848 kJ H2(g) + 1/2 O2(g) --> H2O(g) △H0 = -241.8 kJ H2(g) + 1/2 O2(g) --> H2O(l) △H0 = -285.9 kJ C(s) + 2H2(g) + 1/2 O2(g) --> CH3OH(l) △H0 = -238.6 kJ 2C(s) + 3H2(g) + 1/2 O2(g) --> C2H5OH(l) △H0 = -277.63 kJ 2C(s) + 2H2(g) --> C2H4(g) △H0 = +52.284 kJ 12. Write the expected electron configurations for Cr, Zn, As and Cu. (8 pts) 13. The figure below represents part of the emission spectrum for a one- electron ion in the gas phase. All the lines result from electronic transition from excited states to the n = 3 state. (a) What electronic transitions correspond to lines A and B? (2 pts) (b) If the wavelength of line B is 142.5 nm, calculate the wavelength of line A. (4 pts) (h = 6.6261 * 10^-34 Js; C = 2.9979 * 10^8 m/s) 14. Which of the following statements are false? (4 pts) (a) It takes less energy to add an electron to nitrogen than to carbon because nitrogen will be closer to achieving a noble gas configuration. (b) It takes more energy to add an electron to fluorine than to oxygen because the radius of fluorine is smaller and more repulsion would occur in the p-orbitals. (c) It takes more energy to add an electron to nitrogen than to carbon because of the extra repulsions that would result in the 2p orbitals. 15. In most of its ionic compounds, cobalt is either Co(II) or Co(III). One such compound, containing chloride ion and waters of hydration was analyzed, and the following results were obtained. A 0.256-g sample of the compound was dissolved in water, and excess silver nitrate was add. The silver chloride was filtered, dried, and weighed, and it had a mass of 0.308 g. A second sample of 0.416 g of the compound was dissolved in water and an excess of sodium hydroxide was added. The hydroxide salt was filtered and heated in a flame, forming cobalt(III) oxide. The mass of cobalt(III) oxide formed was 0.145 g. (mass of Ag in 1 mol = 107.9 g, mass of Cl in 1 mol = 35.45 g, mass of Co in 1 mol = 58.93 g) (a) What is the percent composition, by mass, of the compound? (4 pts) (b) Assuming the compound contains one cobalt ion per formula unit, what is the formula? (2 pts) (c) Write balanced equations for the three reactions described.(6 pts) --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 140.112.217.106