推 hank0526 :推~YP真的太強大了XDD 05/19 11:10
推 tan70405 :推樓上 05/21 13:55
課程名稱︰普通化學
課程性質︰必修
課程教師︰林萬寅
開課學院：理學院
開課系所︰化工系
考試日期（年月日）︰2012/4/18
考試時限（分鐘）：110min
是否需發放獎勵金：要 謝謝
（如未明確表示，則不予發放）
試題 :
1. Pt(Z=78) forms a diamagnetic compound [Pt(en)2(CN)2]2+[PtCl2(CN)2]2-,
where en= ethylenediamine (NH2CH2CH2NH2) and C is the coordinating atom
for the cyanato group (CN-). Answer the following questions.
(A) Give the oxidation states and the number of d electrons for Pt in
both ions. [4%]
(B) Name this coordination compound. [3%]
(C) Give the d-electron configurations for the complex cation and aion.[4%]
(D) Draw all possible structures for [Pt(en)2(CN)2]2+. [6%]
(E) Draw all possible structures for [PtCl2(CN)2]2-. [4%]
(F) Estimate the crystal field stabilization energy for [Pt(en)2(CN)2]2+[4%]
2. If each O2 molecule undergoes 4.40*10^9 collisions per second in a 30.0-L
container at 300K and 1.00 atm, answer the following questions.
(A) Calculate the average speed of O2 molecule. [4%]
(B) Find the mean free path of O2 molecule. [4%]
(C) Estimate the molecular diameter (in nm) of O2. [4%]
(D) Estimate the van der Waal's constant b (in L*mol^-1) of O2 ,which is
roughly four times its molar molecular volume. [4%]
(E) If the container is compressed to 1.00L and simultaneously cooled to
200K, the compressibility factor is found to be 0.940.Find the pressure
of the gas. [4%]
(F) Estimate the van der Waal's constant a (in atm*L^2*mol^(-2) ) of O2.[5%]
3. Consider the ocean to be 0.500M NaCl solution. Answer the following
questions. Assume complete dissociation of NaCl; density=1.00g/ml for all
aqueous solutions; Na=23.0; Cl=35.5.
(A) Calculate the osmotic pressure of the ocean at 30.0*C. [3%]
(B) Indicate the direction of water flow when seawater is separated from
pure water by a semipermeable membrane. [3%]
(C) Estimate the minimum work required to transfer 5.00 mol of water from
seawater to pure water through a semipermeable membrane at 30.0*C? [4%]
(D) If the vapor pressure of water at 20.0*C is 17.8 torr, what is the
vapor pressure at 30*C? The molar enthalpy of vaporation for water
is 40.0kJ*mol^(-1). [5%]
(E) Find the vapor pressure of seawater at 30.0*C. [5%]
(F) If 6.00g of a non-dissociating substance X dissolved in 94.0g of water
is isotonic (i.e.,same osmotic pressure) to the seawater, find the
molar mass of X? [5%]
4. The thermodynamic properties for white tin and gray tin at 1 atm are given
below:
substance ΔHf* (KJ*mol^(-1)) S* (J*K^(-1)*mole^(-1)) Density (g*cm^(-3))
-----------------------------------------------------------------------------
white tin 0.00 51.5 7.31
gray tin -2.12 44.1 5.75
Answer the following questions. (Sn=118.7)
(A) Estimate the phase transition temperature (in *C) for gray and white
tin. [5%]
(B) What is the stable form of tin at low temperatures? Explain. [4%]
(C) What is the stable form of tin at high pressures? Explain. [4%]
(D) Calculate the work involved in the transition of 10.1 mol white tin
to gray tin at the phase transition temperature and 1 atm. [6%]
(E) The slope of the phase transition curve is given by dP/dT=ΔS*/ΔV.
Estimate the phase transition temperature for white tin --> gray tin
at 100 atm. Assume ΔS* and ΔV are independent of T and P. [6%]
======================================
以下 附上教授提供的解答!
1.
(A) Pt = +4, d6 for cation; Pt = +2; d8 for anion
(B) dicyanatobis(ethylenediamine)platinum(IV) dichlorodicyanatoplatinate(II)
(C) 略
(D) 略
(E) 略
(F) -12/8Δo
2.
(A) 446 m*s^(-1)
(B) 1.01*10^(-7) m
(C) d=0.301 nm
(D) 0.0344 L*mol^(-1)
(E) P2=18.8 atm
(F) a = 1.40 atm*L^2*mol^(-2)
3.
(A) 24.9 atm
(B) pure water => sea water
(C) 227 J
(D) 30.6 torr
(E) 30.0 torr
(F) 60 g/mol
4.
(A) 13.2*C
(B) white => gray . ΔH*=-2.20 kJ/mol
low T favors the exothermic process ;
gray tin is the stable form at low T
(C) high P favors the dense materials
gray tin is the stable form at high P
(D) -4.46J
(E) 7.2*C
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.112.237.39