Sunday, November 25, 2012

Activity based Questions with answer: X Chapter: Carbon and Its Compounds


Activity based Questions with answer: X Chapter: Carbon and Its Compounds

1. Q. What happen when few drops of alkaline KmNO4 added to Ethanol?

Ans: In the begging color of KmNO4 disappear. When excess KmNO4 is dissolved in solution colour cannot disappear because whole Ethanol gets oxidized into Ethanoic acid.

CH3CH2OH ----- KmNO4------Heat------->CH3COOH

Hence, alkaline KmNO4or Acidified K2Cr2O7 oxidized alcohol into ethanoic acid

2. Q. How can we convert unsaturated hydrocarbon into saturated hydrocarbon?

Ans: By the addition reaction of unsaturated hydrocarbon with halo atom in the presence of catalyst.

HC=CH    +H2 -------------Ni--------5700 K------> Ch3-CH3

R2C=CR2 + H2    ------------Ni---------> R2HC-CHR2 (Vegetable Gee)

This reaction is known as Hydrogenation reaction.

3. Q. How can you test that given hydrocarbon is unsaturated?

Ans: When few drops of Bromine is added to unsaturated hydrocarbon its colour disappear due to addition reaction.

For example: If drops of bromine water added to ethyne, the colour of Bromine disappear due to addition reaction. HCCH + Br2     -------------> HBr2 C – CHBr2 (Tetra room ethane is formed)

4. Q. How can you prepare alkenes from Ethanol?

Ans: When Ethanol heated in presence of Conc.H2SO4 or Al2O3 at 6230C ,Ethanol loose water molecules and form alkenes. C2H5OH ---H2SO4------6230C------>CH2=CH2    + H2O

5. Q. What happen when a piece of sodium metal added to Ethanol?

Ans: Sodium ethoxide is formed with evolution of H2 gas

C2H5OH         + Na -------------> C2H5ONa    + H2

6. Q. What happens when few drops of Conc.H2SO4 is added to Solution of Ethanoic acid and Ethanol?

Ans: A substance with fruity smell is formed called Ester.This reaction is known as Esterification

C2H5OH + CH3COOH ------H2SO4------> CH3COO C2H5 (Ester or, Ethyl Ethanoate)

7. Q. What types of flame produce by burning of Benzene, Nepthline and Camphor?

Ans: Smoky flame due presence of excess carbon content.

8. Q. What is Gasol?

Ans: The mixture of petrol with alcohol up to 20% is known gasol.

9.Q. Why Acetic acid is called glacier acid?

Ans: Acetic acid freezes at 290K in cold weather and form crystals.This is why acetic acid is called glacier acid.

10. Q. What is saponification?

Ans: When sodium hydroxide react with ester and form alcohol and sodium Ethanoate. This reaction is used to form soap So this reaction is known as saponification.

CH3COO C2H5     +     NaOH  ------------>  CH3COONa   + C2H5OH
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