课程名称︰无机化学一 课程性质︰必修 课程教师︰彭旭明 开课学院：理学院 开课系所︰化学系 考试日期（年月日）︰2011/1/12 考试时限（分钟）：120 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : 1.Draw the lewis structure and give the point group of the following molecules (with highest possible symmetry.)(10%) (a)sulfuric acid (b)nitric acid (c)Phosphoric acid (d)perchloric acid (e)hydrazoic acid (HN3) 2.Draw the 3-dimensional structure and give the point group of the following species.(10%) (a)ferrocene (b)diborane (c){Re2Cl8}2- (d)S8 (e){K(18C6)}+(in which, 18C6=18-Crown-6) 3.For each of the following reactions, identify the acid and the base. Also indicate which acid-base definition (Lewis, Solvent system, Bronsted- Lowry) applies. In some cases, more than one definition may apply.(10%) (a)HClO4 + CH3CN >>>> CH3CNH+ + ClO4- (b)PCl5 + ICl >>>> {PCl4}+ + {ICl2}- (c)2 ClO3- + SO2 >>>> 2 CLO2 + SO42- (d)2 NOCl + Sn >>>> SnCl2 + 2NO (in N2O4 solvent) (e) BH4- + 4 H2O >>>> B(OH)4- + 4 H2 4. Use drago's E and C parameters(Table1) to calculate deltaH for the reaction of pyridine and BF3 and of pyridine and B(CH3)3. Repeat the calculations of the proceeding problem using NH3 as the base, and put the four reactions in order of the magnitudes of their deltaH values.(6%) Table1 CA, EA , CB and EB values (kcal/mol) acid compound CA EA B(CH3)3 1.70 6.14 BF3 1.62 9.88 base compound CB EB pyridine 6.40 1.17 NH3 3.46 1.36 5.List the following acids in order of acid strength in aqueous solution. (Hint: Use pauling's equation):(6%) a. HMnO4 H3AsO4 H2SO3 H2SO4 b. HClO HClO4 HClO2 HClO3 6.HF has H0=-11.0 Addition of 4% SbF5 lowers H0 to -21.0. Explain why this should be true, and why the resulting solution is so strongly acidic that it can protonate alkenes. (4%) (CH3)2C=CH2 + H+ >>>> (CH3)3C+ 7. Diagram A shows some subjects and B shows some optical transforms. Match the objects to the transforms and determine their correct relative orientations. (12%) (a) o (b) O (c)0 (d). (e)(f)(g)(h)(i)(j)(k)(l)过於复杂 故略 0 . . . . (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)too complicated, skip 8. F(hkl)=sigma(fjexp(2pii(hxj+kyi+lzj) p(x, y, z)=sigmahsigmaksigmal(Fhkl)exp(ia)exp(-2pii(hx+ky+lz) Explain the meaning of each term in the two equations. (12%) 9.(a)Show that spheres occupy 74.0% of the total volume in a face- centered cubic structure in which all atoms are identical. (b)What percent of the total volume is occupied by spheres in a body- centered cube in which all atoms are identical.(8%) 10.LiBr has a density of 3.464g/cm^3 and the NaCl crystal structure. Calculate the interionic distance, and compare your answer with the valuse from the sum of the ionic radii found in Table.2 (6%) (the fornula weight of LiBr is 86.85 g/mol) Table 2 ionic radii Coordination Number Ionic 4 6 8 Li+ 73 90 pm 106 Br- -- 182 -- 11.Derive the lattice energy (U) from electrostatic energy and short distance repulsion energy at r-ro(10%) U=NMZ+Z-e^2*(1-1/n)/r0 12.Focusing on the boron atoms and the bridging hydrogens of diborane as Fig.1, we can use table 3 to sketch the group orbitals and detetmine their matching irreducible representations (8%) (a)Show that the representation T(pz) reduces to Ag + B1u (b)SHow that the representation T(px) reduces to B2g + B3u. (c)show that the representation T(1s) reduces to Ag + B3u. (d)Verify that the sketches for the group orbitals match their respective symmetry designation (Ag, B2g, B1u, B3u) in Table 3. (Please use the fill-in-the-blank form of Table 4 to answer(d)) Table 3 Character Table E C2(z) C2(y) C2(x) i sigma(xy) sigma(xz) Sigma(yz) Ag 1 1 1 1 1 1 1 1 B1g 1 1 -1 -1 -1 1 -1 -1 B2g 1 -1 1 -1 1 -1 1 -1 B3g 1 -1 -1 1 -1 1 1 -1 Au 1 1 -1 1 1 -1 -1 1 B1u 1 -1 1 1 -1 1 1 -1 B2u 1 -1 1 -1 -1 1 -1 1 B3u 1 -1 -1 1 -1 1 1 -1 Table 4 designations group orbitals sketches Ag pz B1u B2g px B3u Ag s B3u 13.The reaction P4(g) >>>> 2 P2(g) has deltaH=217kj/mol. If the bond energy of a single phosphorous-phosphorous bond is 200kj/mol, calculate the bond energy of the pp triple bond/ Compare the value you obtain with the bond energy in N2 (946 kj/mol), and suggest an explanation for the difference in bond energies in P2 and N2.(6%) 14.BrF3 undergoes autodissociation according to the equilibrium 2BrF3 >>>> BrF2+ + BrF4- ionic fluorides such as KF behave as base in BrF3, whereas some covalent fluorides such as SbF5 behave as acids. On the basis of the solvent system concept, write balanced chemical equations for these acid-base reactions of fluorides with BrF2.(4%) 15.Give thename in English, indicate their magnetic properties (paramagnetic, diamagnetic) and rationalize the bond distance.(12%) Formula Name Magnetic property o-o Distance(pm) O2+ 111.6 O2 120.8 O2- 135 O22- 149 O3 127.8 O3- 134 --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 114.42.72.101