98 CE 2題 - Ans.fyi 參考答案

98 CE 2題

2008-04-28 7:41 am

12. A gas X is bubbled into a solution of Y as shown in the above diagram.
In which of the following combinations would X react with Y ?
X Y
A.Ammonia Potassium nitrate
B.Chlorine Potassium nitrate
C.Carbon dioxideSodium hydroxide
D.Sulpur dioxideIron (II) sulphate

29 .X is a compound containing four carbon atoms. It gives negative results
with the following tests.
Test
(1) Treating X with sodium hydrogencabonate solution.
(2) Treating X with a solution of bromine in 1, 1, 1-trichloroethane.
(3) Heating X with acidified potassium dichromate solution.
The structure formula of X may be.
A. CH3CH2CH=CH2.
B. CH3CH2CH2CH2OH.
C. CH3CH2CH2CO2H.
D. CH3CH2CH2CH3.

44. Upon heating , a mixture of iron and sulphur gives a black substance.
Which of the following statements concerning the black substance are
correct?
(1) It is insoluble in water.
(2) It can be attracted by a bar magnet.
(3) It reacts with dilute hydrochloric acid to give a gas with a pungent smell.
A. (1) and (2) only
B. (1) and (3) only
C. (2) and (3) only
D. (1),(2) and (3)

第12, 44題請提供equation
仲有, 點解potassium permanganate 要用 brown bottle 保存?

回答 (1)

Audrey Hepburn

2008-04-29 5:05 am

✔ 最佳答案

12. The answer is C.
For A and B, there areno reactions.
For C: 2NaOH(aq)+ CO2(g) → Na2CO3(aq) + H2O(l)
So, there is a reaction.
For D, sulphurdioxide and iron (II) sulphate are reducing agents, so they will not havereaction with each other.

29. The answer is D.butane CH3CH2CH2CH3.
Reaction in (1), option Cbutanoic acid will have reaction with sodium hydrogencarbonate solution. This isa reaction between acid and alkali and it is neutralzation.
For (2), option Abut-1-ene will have addition reaction with bromine in orgainic solvent.
For (3), option B butanolwill have reaction with acidified potassium dichromate solution under heatingto give butanoic acid.
For the three teststo give negative results, D is the answer.

44. The answer is B. (1)and (3) only.
Chemical equation: Fe(s)+ S(s) → FeS(s)
(1) The product is iron (II) sulphide, it isinsoluble in water.
(2) It cannot be attracted by a bar magnet.
(3) FeS(s) + 2HCl(aq)→ FeCl2(aq) + H2S(g)
Hydrogen sulphide isthe gas prodcued which gives a pungent smell.

Town gas consistsmainly hydrogen and methane. Sometimes carbon monoxide is included.

參考: Myself~~~

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