更新1:
其實我係想對答案， 我的答案: A,A,B,C,B,B,A,D,B,A
9 mc questions
2012-01-06 2:04 am
27) Electrolysis of dilute sulphuric acid forms twogas, the ratio between amount of gas produced in positive electrode to amountof gas produced in negative electrode isA. 1:2B. 1:1C. 1:5D. 2:1 28) Which of the following ions would migrate tothe cathode during electrolysis of molten lead(II) bromide?A. Pb2+B. H+C. Pb2+ and Br-D. H+ and Br- 29) Which of the following pairs of molecules havedifferent shape?A. CH4 and SiCl4B. CO2 and SO2C. H2O and H2SD. NH3 and PCl3 30) Which molecules has zero net dipole moment?A. CH2Cl2B. HNO3C. BCl3D. Cl2O 31) Which of the following is insoluble in water?A. ethanolB. propaneC. ethanoic acidD. dimethyl ether (methoxymethane) 32) Which of the following is the correct ascendingorder of voscosityA. pentane < propanoic acid < acetoneB. pentane < acetone < propanoic acidC. propanoic acid < acetone < pentaneD. acetone < propanoic acid < pentane 33) An alkane X has the molecular formula C5H12,how many possible structure does X have?A. 2B. 3C. 4D. 5 34) Which of the following combinations isINCORRECT?A. Alkane has general formula of C(n)H(2n+2)B. Alkene has general formula of C(n)H(2n)C. Alkanol has general formula of C(n)H(2n+1)OHD. Alkanoic acid has general formula of C(n)H(2n)COOH 35) Which of the following about straight-chained hydrocabonsC2H4, C3H6 and C4H10 is correct?A. They belongs to the same homologous seriesB. They are gases at room temperature and pressureC. They have same boiling pointD. The relative molecular mass of each successivecompound differ by 14 36) For the complete combustion of hexane, w moleof hexane react with x mole of oxygen to form y mole of CO2 and z mole of water;what are w, x, y and z?A. w=2, x=19, y=12 and z = 14B. w=1, x=9, y=6 and z = 6C. w=2, x=16, y=10 and z = 12D. w=1, x=13, y=6 and z = 7
回答 (3)
2012-01-07 5:55 am
✔ 最佳答案
小心! 001號答題者純粹是亂答亂寫字母;
002號答題者只是廣告.
2012-01-06 21:55:44 補充：
澄清過就好多了, 免得招來誤會.
小心!
001號答題者純粹是亂答, 亂寫字母;
002號答題者只是廣告.
27. correct.
oxidation occurs at +ve electrode, where O in hydroxide is oxidized to give O2; another electrode gives H2.
2H2O ------> 2H2 + O2
volume ratio = mole ratio.
28. correct.
reduction occurs at cathode (RED--CAT), which electrode provides electrons; thus cathode carries -ve charge. cations are attracted.
in molten PbBr2, only cation is Pb(2+); no water is present, so no H(+).
29. correct.
count the no. of groups of electrons.
30. correct.
BCl3 is a planar molecule, with all 3 equivalent B-Cl bonds stretching outward.
31. correct.
propane is non-polar and cannot form hydrogen bonds with water.
32. correct.
viscosity is directly proportional to the strength of intermolecular attraction.
H-bond > polar-polar interaction > weak Van der waal's force (instantaneous dipole thing).
33. sorry to tell you, incorrect.
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there're 3 isomers, namely: pentane, (2-)methylbutane, (2,2-)dimethylpropane.
(I wonder if the numbers for positions are necessary, as there's no other possible structure for each of them)
34. correct.
alkanoic acid is C(n)H(2n+1)COOH
35. correct.
hydrocarbons with 4 or less carbons are gaseous under Rm. temp. & pressure.
36. correct.
remember this equation:
CxHy + (x + y/4) O2 ------> xCO2 + (y/2) H2O
substitute x=6, y=14 to equation, then multiply the whole equation by 2 to obtain integer coefficients.
2012-01-06 2:44 am
以下是雅虎搜查結果:
http://hk.search.yahoo.com/searc ... tab-web-t&rd=r1
或者你可以直接去官網search睇睇有冇你要的東西，
http://www.okonlineshop.com
希望能幫到你!
http://hk.search.yahoo.com/searc ... tab-web-t&rd=r1
或者你可以直接去官網search睇睇有冇你要的東西，
http://www.okonlineshop.com
希望能幫到你!
2012-01-06 2:34 am
27. C
28. D
29. C
30. A
31. A
32. B
33. B
34. D
35. B
36. A
28. D
29. C
30. A
31. A
32. B
33. B
34. D
35. B
36. A
收錄日期: 2021-04-20 12:02:27
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20120105000051KK00703