※ [本文轉錄自 NTU-Exam 看板] 作者: leehoni (leehoni) 看板: NTU-Exam 標題: [試題] 林英智 普通化學甲 時間: Sat Nov 12 21:31:09 2005 課程名稱︰普通化學甲 課程性質︰必修 課程教師︰林英智 開課系所︰化學系 考試時間︰2005/10/26 試題 : 1.Consider an atom of 64Zn(10%) (a)Calculate the density of the uncleus in grams per cubic centimeter,knowing that the nuclear radius is 4.8*10^-6 nm and the mass of the 64Zn atom is 1.06*10^22g. (b)Calculate the density of the space occupie by the electrons in the zinc atom, given that the atomic radius is 0.125nm and the electron mass is 9.11*10^-28g. (c)Having calculated the previous densites,what statement can you make about the relative densites of the parts of the atom? 2.To estimate the radius of a lead atom:(10%) (a)You are given a cube of lead that that is 1.000cm on each side.The density of lead is 11.35g/cm^3.How many atoms of lead are contained in the sample? (b)Atoms are spherical;therefore,the lead atoms in this sample cannot fill all the available space.As an approximation,assume that60% of the space of the cube is filled with spherical lead atom.(Pb=207.2) 3.The element AandZ combine to produce two different compounds:A2Z3 and AZ2.If 0.15mol of A2Z3 has a mass of 15.9g and 0.15mol of AZ2 has a mass of 9.3g,what are the atomic masses of A and Z?(10%) 4.Uranium is use as a fuel,primarily in the form of uranium(IV)oxide,in nuclear power plants.This question considers some uranium chemistry.(U=238.029)(10%) (a)A small sample of uranium metal(0.169g)is heated to between 800 and 900℃ in air to give 0.199g of a dark green oxide,UxOy,What amount of uranium metal was used?What is the empirical formula of the oxide UxOy? What is the name of the oxide?What amount of UxOy must have been obtained? (b)The naturally occuring isotopes of uranium are234U,235U,and238U.Which is the most abundant? (c)If the hydrated compound UO2(NO3)2.zH2O is heated gently,the water of hydration is lost.If you have 0.865g of the hydrated compound and obtain 0.679g of UO2(NO3)2 on heating, how many molecules of water of hydration are in each formula unit of the original compound?(The oxie UxOy is obtained if the hydrate is heated to temperatures over 800℃ in the air.) 5.An herbicide contain 2,4-D(2,4-dichlorophenoxyacetic acid),C8H6Cl2O3.A 1.236g sample of the herbicide is decomposed to liberate the chlorine as Cl-ion. This was precipitated as AgCl,with a mass of 0.1840g.What is the mass precent of 2,4-D(2,4-dichlorophenoxyacetic acid)in the sample?(Ag=107.9 Cl=35.45)(10%) 6.Calculated ΔH,ΔE,q and w for a 1 mol of monoatomic ideal gas system from a state of 2 atm and 10L to a state of 3 atm and 15L via(a)a constant pressure process(to 2 atm 15L first) followed by a constant volumn process(to 3 atm and 15L final state).(b)a constant volume process followed by a constant pressure process.(20%) 7.Fin the work for an isothermal expansion from a state of 2 atm and 10L to 0.5 atm for 1.2 mole of ideal gas. What is ΔH,ΔE and q for this procss?(10%) 8.Naming the following compound:(10%) (a)CuCl(b)Na2So3(c)HClO2(d)HClO3(e)HCl 9.For an adiabatic expasion(q=0,no heat exchange) of an ideal gas from 10 atm 10L at 0℃ to 1 atm.Find the final volume and temperature of the system.(Cv= 3R/2 and Cp=5R/2 where P is a gas constant)(10%) 10.Assuming that the combustion of hydrogen gas provide three times as mush energy per gram as gasoline,calculate the volumn of liquid H2(density=0.0710 g/mL)required to furnish the energy contained in 80.0L(about 20 gal)of gasoline (density=0.740g/mL).Calculate also the volumn that this hydrogen would occupy as a gas 1.00atm and 25℃.(T=273+℃,R=0.08206L atm K^-1 mol^-1) (10%) 11.Diborane(B2H6)is a highly reactive boron hyride,which was once considered as a possible rocket fuel for U.S.space program.Calculate ΔH for the synthesis of diborane form is element,according to the equaction 2B(s) + 3H2(g) → B2O6(g) using the following data:(10%) reaction ΔH (a)2B(s) + 3/2O2(g) → B2O3(s) -1273kj (b)B2H6(g) + 3O2(g) → B2O3(s) + 3H2O(g) -2053kj (c)H2(s) + 1/2O2(g) → H2O(l) -286kj (d)H2O(l) → H2O(g) 44kj --

※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 218.167.47.19 --

※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 218.160.125.117