课程名称︰普通化学乙上 General Chemistry (B) 课程性质︰必修 课程教师︰彭旭明 开课学院： 开课系所︰心理系 森林系 考试日期（年月日）︰2012年1月11日 考试时限（分钟）：110分钟 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : 1.Give the order in decreasing radius:(选项为离子) (a)Be, Mg, Ba. (b)N3-, O2-, F-.(c)Tl3+, Tl2+, Tl+.(6%) 2.The formula for calculating the energies of an electron in a hydrogen like ion is: E(n)=-(2.18x10^(-18)J) x Z^(2) x (1/N^(2)) This equation cannot be applied to many-electron atoms. One way to modify it for the more conplex atoms is to replace Z with (Z-σ), in which Z is the atomic number and σ is a positive dimensionless quantity called the shielding constant. Consider the helium atom as an example. The physical significance of σ is that it represents the extent of shielding that the two 1s electrons exert on each other. Thus, the quantity (Z-σ) is appropriately called the "effective nuclear charge." Calculate the value of σ if the first ionization energy of helium is 3.94x10^(-18)J per atom.(Ignore the minus sign in the given equation in your calculation.)(6%) 3.Match each of the elements on the right with its description on the left: (a) A greenish-yellow gas that reacts with water. Nitrogen(N2) (b) A soft metel that reacts Boron(B) with water to produce hydrogen. Aluminum(Al) (c) A metalloid that is hard Fluorine(F2) and has a high melting point. Sodium(Na) (d) A colorless, oderless gas. (e) A more reactive metel than iron, which does not corrode in air. (5%) 4.Draw the Lewis structure and sketch the molecular geometry of the following molecules: (a) H2SO4, (b) HNO3, (c)H3PO3 (One H is bonded to P), (d)CO, (e)O3, (f)SF4 (g)IF5, (h)SOF4, (i)SO3, (j)HN3 (azidic acid) (20%) 5.True or false:(4%) (a) Formal charges represent actual separation of charges; (b) ΔH0rxn can be estimated from bond enthalpies of reactants and products; (c) All second-period elements obey the octet rule on their compounds; (d) The resonance structures of a molecule can be separated from one another. 6. (a)Draw three resonance structures of these two linear ions N3- and N5+ respectively, showing all their formal charges.(6%) (b)Refer to the following table, please calculate the reaction enthalpy change of the reaction: N5+ + N3-(g) → 4N2(g) [Assuming lattice energy is neglected] (4%) Bond Bond Enthalpy(kJ/mol) N－N 193 N＝N 418 N≡N 941.4 7.Write the Lewis structures, bond orders, magnetic properties of O2, O2+(O2的一价阳离子), O2-(O2的一价阴离子) and compare their bond length.(10%) 8.Sketch the shapes of these molecular orbitals: σ1s, σ1s*, π2p, and π2p*. How do their energies compare?(8%) 9.Antimony Pentaflouride, SbF5, reacts with XeF4 and XeF6 to form ionic compounds, XeF3+SbF6- and XeF5+SbF6-. Describe the geometries of the cations and anion in these two compounds.(4%) 10.The allene molecule H2C＝C＝CH2 is linear (the three C atoms lie on a straight line). What are the hybridization states of the carbon atoms? Draw diagrams to show the formation of sigma bonds and pi bonds in allene.(6%) 11.Draw Newman projections of four different conformations of butane. Rank them in stability.(Hint: Two of the conformations represent the most stable forms and the other two the least stable forms.)(6%) 12.Draw all the possible isomers of C5H10 and name them.(10%) 13.Predict the products of each of these reactions:(6%) (a)CH3CH2OH + HCOOH → (b)H－C＝C－CH3 + H2 → (c) C2H5 H ╲╴／ ／￣╲ + HBr → H H 14. Indicate the asymmetric carbon atoms in these compounds: CH3 O ∣ ∥ (a) CH3－CH2－CH－CH－C－NH2 ∣ NH2 (b) H | H C H |╱|╲| C Br C | ￣￣| H H --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 1.162.87.40