CBSE Class 10 Science Important Questions Chapter 4 Carbon and Its Compounds Part 5

Get top class preparation for CBSE right from your home: fully solved questions with step-by-step explanation- practice your way to success.

Download PDF of This Page (Size: 486K)

5 Marks Questions

1. Define fermentation. Name the enzyme which converts

(a) Milk into curd (yogurt)

(b) Cane sugar into glucose and fructose.

(c) Glucose into ethanol

Ans. The preparation of ethyl alcohol from sugar is known as fermentation.

(a) Lactase converts milk into curd

(b) Invertase converts cane sugar into glucose and fructose

(c) Zymase converts glucose into ethanol.

2. (a) Name the gas evolved during fermentation process?

(b) What role is played by yeast in the conversion of cane sugar to ethanol?

(c) How may the following be obtained from pure ethanol? Express s chemical reactions by the chemical equations.

(i) Sodium ethoxide

(ii) Ethyl ethanoate

(iii) Ethanal

Ans. (a) gas is evolved accompanied by brisk effervescence.

(b) Yeast is the source of enzymes invertase and Zymase needed for fermentation.

(c) (i)

(ii)

(iii)

3. An organic compound A is widely used as a preservative in pickles and has a molecular formula . This compound reacts with ethanol to form a sweet smelling compound B.

(a) Identify the compound A.

(b) Write the chemical equation for its reaction with ethanol to form compound B.

(c) How can we get compound A back from B.

(d) Name the process and write the corresponding chemical equation.

(e) Which gas is produced when compound A reacts with washing soda? Write the chemical equation?

Ans. (a) Compound A is ethanoic acid

Compound A is ethanoic acid

Compound a is Ethanoic Acid

Compound A is ethanoic acid

(d) The process is known as ester hydrolysis.

(e) is produced with effervescence when compound A reacts with washing soda which is chemically

4. (a) Why does carbon form largest number of compounds?

(b) Why are some of these called saturated and other unsaturated compounds?

(c) Which of these two is more reactive?

(d) Write the names of the following compounds

(i)

(ii)

Ans. (a) Carbon forms large number of compounds called organic compounds due to the self-linking property called catenation.

(b) Compounds which has only C-C (single bond) present are saturated compounds whose as those compounds which has C=C (double bond) or CC (triple) bond is present are called unsaturated compounds.

(c) Unsaturated compounds are more reactive than saturated compounds

(d) (i) Bromoethane

(ii) Hex-1-yne

5. Draw the structure for the following compounds:

(i) Ethanoic acid

(ii) Bromopentane

(iii) Butane

(iv) Hexanal

Ans. Structure of compounds are given as under:

(i) Ethanoic acid

Ethanoic acid

Ethanoic Acid

Ethanoic acid

(ii) Bromopentane

Bromopentane

Bromopentane

Bromopentane

(iii) Butanone

Butanone

Butanone

Butanone

(iv) Hexanal

Hexanal

Hexanal

Hexanal

6. Draw the electron dot structure for

(a) Ethanoic acid

(b)

(c) Propanone

(d)

Ans. (a) Ethanoic acid

Ethanoic acid

Ethanoic Acid

Ethanoic acid

(b)

H 2 S

H 2 S

H 2 S

(c) Propanone

Propanone

Propanone

Propanone

(d)

F 2

F 2

F 2

7. Why does micelle formation take place when soap is added to water? Will a micelle be formed in other solvents such as ethanol also?

Ans. Soap is sodium or potassium salt of long chain fatty acid. Two ends of soap molecules have different properties. The ionic end is hydrophilic. It dissolve in water while the hydrogen chain is hydrophobic, it dissolve in hydrocarbon. The hydrocarbon chains are oriented towards the oil droplet while the ionic ends are oriented towards water.

Micelles formation

Micelles Formation

Micelles formation

Micelles formation will not take place in ethanol.

8. An organic compound ‘A’ is widely used as a preservative in pickles and has a molecular formula C This compound reacts with ethanol to form a sweet smelling compound ‘B.

(i) Identify the compound ‘A’

(ii) Write the chemical equation for its reaction with ethanol to form compound ‘B’.

(iii) How can we get compound ‘A’ back from ‘B’?

(iv)Name the process and write corresponding chemical equation.

(v) Which gas is produced when compound ‘A’ reacts with washing soda?

Write the chemical equation.

Ethanoic acid

Ethanoic Acid

Ethanoic acid

(iii) Easter react in the presence of an acid or a base to give back the alcohol and carboxylic acid.

(iv) Saponification

(v) gas evolved

Developed by: