Carbon and its

Compounds
Objective Section (1 mark each)

Note: Two statements are given-one labelled sodium salt of carboxylic acid are
Assertion (A) and the other labelled Reason obtained. [CBSE Delhi, Set 1, 2020]
(R). Select the correct answer to these questions
Q. 2. Assertion (A): In a homologous series
from the codes (a), (b), (c) and (d) as given of alcohols, the formula for the second
below: member is C2H5OH and the third
(a) Both (A) and (R) are true and (R) is correct member is C3H7OH.
explanation of the assertion. Reason (R): The difference between the
(b) Both (A) and (R) are true but (R) is not the molecular masses of the two consecutive
correct explanation of the assertion. members of a homologous series is 144.
(c) (A) is true but (R) is false. [CBSE Delhi, Set 2, 2020]
(d) (A) is false buy (R) is true.
Q. 1. Assertion (A): Esterification is a process
in which a sweet smelling substance is
produced.
Reason (R): When ester react with
sodium hydroxide an alcohol and

Very Short Answer Type Questions (1 mark each)

Q. 1. Name the functional group present in (a) The colour of the mixture has
propanone. [CBSE Delhi, Set 2, 2020] become dark brown.
Q. 2. Name cyclic unsaturated carbon (b) A brisk effervescence is taking
compound. [CBSE Delhi, Set 1, 2020] place in the beaker.
(c) The outer surface of the beaker has
Q. 3. Write the molecular formula of the 2nd become hot.
and the 3rd member of the homologous (d) The outer surface of the beaker has
series whose first member is methane. become cold.
[CBSE OD, Term 2, Set 1, 2017] [CBSE OD, Term 2, Set 1, 2017]
Q. 4. While studying the saponification Q. 5. A student requires hard water for an
reaction, what do you observe when experiment in his laboratory which is not
you mix an equal amount of colourless available in the neighbouring area. In the
vegetable oil and 20% aqueous solution laboratory there are some salts, which
of NaOH in a beaker? when dissolved in distilled water can
convert it into hard water. Select from the
following groups of salts, a group, each
salt of which when dissolved in distilled
water will make it hard.
 (a) Sodium chloride, Potassium chloride (a) P and Q (b) P and R
(b) Sodium sulphate, Potassium sulphate (c) P, Q and S (d) Q, R and S
(c) Sodium sulphate, Calcium sulphate [CBSE Delhi, Term 2, Set 1, 2017]
(d) Calcium sulphate, Calcium chloride Q. 11. Write the molecular formula of first two
[CBSE OD, Term 2, Set 1, 2017] members of homologous series having
functional group Br
[CBSE Delhi, Term 2, Set 2, 2017]
Q. 6. Write the molecular formula of the 2nd
and 3rd member of the homologous Q. 12. Write the molecular formula of first two
series whose first member is ethene. members of homologous series having
[CBSE OD, Term 2, Set 2, 2017] functional group OH.
[CBSE Delhi, Term 2, Set 3, 2017]
Q. 7. Write the molecular formula of the 2nd
and 3rd member of the homologous Q. 13. Which of the following sets of materials
series where the first member is ethyne. can be used for conducting a saponification
[CBSE OD, Term 2, Set 3, 2017] reaction for the preparation of soap?
(a) Ca(OH)2 and neem oil
Q. 8. Write the molecular formula of first two (b) NaOH and neem oil
members of homologous series having
(c) NaOH and mineral oil
functional group Cl.
(d) Ca(OH)2 and mineral oil
[CBSE Delhi, Term 2, Set 1, 2017]
[CBSE Delhi, Term 2, Set 1, 2016]
Q. 9. For demonstrating the preparation of
soap in the laboratory which of the Q. 14. Write the name and structure of an
following combination of an oil and a alcohol with three carbon atoms in its
molecule.
base would be most suitable?
(a) Mustard oil and calcium hydroxide [CBSE OD, Term 2, Set 1, 2016]
(b) Castor oil and calcium hydroxide Q. 15. A student puts a drop of reaction
(c) Turpentine oil and sodium mixture of a saponification reaction first
hydroxide on a blue litmus paper and then on a red
(d) Mustard oil and sodium hydroxide. litmus paper. He may observe that:
[CBSE Delhi, Term 2, Set 1, 2017] (a) There is no change in the blue litmus
paper and the red litmus paper turns
white.
Q. 10. A student took four test tubes P, Q, R (b) There is no change in the red litmus
and S and filled about 8 ml. of distilled paper and the blue litmus paper
water in each. After that he dissolved turns red.
an equal amount of Na2SO4 in P, K2SO4
in Q, CaSO4 in R and MgSO4 in S. On
adding an equal amount of soap solution
and shaking each test tube well, a good
amount of lather will be obtained in the
test tubes:
 (c) There is no change in the blue litmus (a) P and Q (b) R and S
paper and the red litmus paper turns (c) P, Q and R (d) P, Q and S
blue.
[CBSE Delhi, Term 2, Set 1, 2016]
(d) No change in colour is observed in
both the litmus papers. Q. 21. Consider the following comments about
[CBSE OD, Term 2, Set 1, 2016] saponification reactions:
I Heat is evolved in these reactions.
Q. 16. For preparing soap in the laboratory
we require an oil and a base. Which of II For quick precipitation of soap
the following combinations of an oil sodium chloride is added to the
and a base would be best suited for the reaction mixture.
preparation of soap? III Saponification reactions are special
(a) Castor oil and calcium hydroxide kind of neutralisation reactions.
(b) Turpentine oil and sodium IV Soaps are basic salts of long chain
hydroxide fatty acids.
(c) Castor oil and sodium hydroxide
(d) Mustard oil and calcium hydroxide The correct comments are:
[CBSE OD, Term 2, Set 1, 2016] (a) I, II and III (b) II, III and IV
(c) I, II and IV (d) Only I and IV
Q. 17. Write the name and structure of an
alcohol with four carbon atoms in its [CBSE Delhi, Term 2, Set 1, 2016]
molecule. Q. 22. Name the following compounds:
[CBSE OD, Term 2, Set 2, 2016]
(a) CH3—CH2—OH;
H
(b) CH3 C O
Q. 18. Write the name and structure of an [CBSE Delhi, Term 2, Set 2, 2016]
aldehyde with four carbon atoms in its Q. 23. Select saturated hydrocarbons from the
molecule. following:
[CBSE OD, Term 2, Set 3, 2016] C3H6; C5H10; C4H10; C6H14; C2H4
Q. 19. Write the next homologue of each of the [CBSE Delhi, Term 2, Set 3, 2016]
following:
(i) C2H4 (ii) C4H6 Q. 24. Write the number of covalent bonds in
[CBSE Delhi, Term 2, Set 1, 2016] the molecule of ethane.
[CBSE OD, Term 2, Set 1, 2015]
Q. 20. A student takes four test tubes marked
P, Q, R and S of 25 mL capacity and fill Q. 25. While preparing soap a small quantity
10 mL of distilled water in each. He of common salt is generally added to
dissolves one spoon full of four different the reaction mixture of vegetable oil and
salts in each as KCl in P, NaCl in Q, CaCl2 sodium hydroxide. Which one of the
in R and MgCl2 in S. He then adds about following may be the purpose of adding
2 mL of a sample of soap solution to common salt?
each of the above test-tubes. On shaking (a) To reduce the basic nature of the soap
the contents of each of the test-tubes, he (b) To make the soap neutral
is likely to observe a good amount of
lather (foam) in the test tubes marked:
 (c) To enhance the cleansing power of (iii) The beaker containing solution
the soap appears cold when touched from
(d) To favour the precipitation of the outside.
soap (iv) The blue litmus paper turns red
[CBSE OD, Term 2, Set 1, 2015] when dipped into the solution
Q. 26. Write the number of covalent bonds in The correct observations are:
the molecule of propane, C3H8. (a) I, II and IV
[CBSE OD, Term 2, Set 2, 2015] (b) I, II, and III
(c) only III and IV
(d) only I and II
[CBSE Delhi, Term 2, Set 1, 2015]
Q. 30. Hard water is not available for an
experiment. Some salts are given below:
Q. 27. Write the number of covalent bonds in (i) Sodium chloride
the molecule of butane, C4H10. (ii) Sodium sulphate
(iii)Calcium chloride
[CBSE OD, Term 2, Set 3, 2015]
(iv) Calcium sulphate
Q. 28. Write the name and formula of the 2nd (v) Potassium chloride
member of homologous series having (vi) Magnesium sulphate
general formula CnH2n. Select from the following a group of
[CBSE Delhi, Term 2, Set 1, 2015] these salts, each member of which may
Q. 29. A student prepared 20% sodium be dissolved in water to make it hard.
hydroxide solution in a beaker to (a) I, II, V (b) I, III, V
study saponification reaction. Some (c) III, IV, VI (d) II, IV, VI
observations related to this are given [CBSE Delhi, Term 2, Set 1, 2015]
below:
Q. 31. Write the name and formula of the 2nd
(i) Sodium hydroxide solution turns
member of homologous series having
red litmus blue
general formula CnH2n+2.
(ii) Sodium hydroxide readily dissolves
[CBSE Delhi, Term 2, Set 2, 2015]
in water
Q. 32. Write the name and formula of the 2nd
member of homologous series having
general formula CnH2n–2.
[CBSE Delhi, Term 2, Set 3, 2015]

Short Answer Type Questions-I (2 marks each)

Q. 1. Write the molecular formula of ethene

and draw its electron dot structure.
[CBSE OD, Set 1, 2019]
Q. 2. Draw electron dot structure of carbon Q. 6. In three test tubes A, B and C, three
dioxide and write the nature of bonding different liquids namely, distilled water,
between carbon and oxygen in its molecule. underground water and distilled water
[CBSE OD, Set 2, 2019] in which a pinch of calcium sulphate is
dissolved, respectively are taken. Equal
amount of soap solution is added to each
Q. 3. List two properties of carbon which
test tube and the contents are shaken. In
lead to the huge number of carbon
which test tube will the length of the
compounds we see around us, giving
foam (lather) be longest? Justify your
reason for each. [CBSE OD, Set 2, 2019]
answer. [CBSE Delhi, Set 1, 2019]
Q. 7. A compound ‘X’ on heating with excess
conc. sulphuric acid at 443 K gives an
unsaturated compound ‘Y’. ‘X’ also
reacts with sodium metal to evolve a
colourless gas ‘Z’. Identify ‘X’, ‘Y’ and
‘Z’. Write the equation of the chemical
reaction of formation of ‘Y’ and also
write the role of sulphuric acid in the
Q. 4. List two chemical properties on the basis
reaction. [CBSE, 2018]
of which ethanol and ethanoic acid may
be differentiated and explain how.
[CBSE OD, Set 3, 2019]
Q. 8. Mention the essential material
Q. 5. Unsaturated hydrocarbons contain (chemicals) to prepare soap in the
multiple bonds between two carbon laboratory. Describe in brief the test of
atoms and these compounds show determining the nature (acidic/alkaline)
addition reactions. Out of saturated and of the reaction mixture of saponification
unsaturated carbon compounds, which reaction. [CBSE OD, Term 2, Set 1, 2017]
compounds are more reactive? Write a
test to distinguish ethane from ethene.
[CBSE OD, Set 3, 2019]
Q. 9 . A student adds a spoon full of powdered
sodium hydrogen carbonate to a flask
containing ethanoic acid. List two main
observations, he must note in his note
book, about the reaction that takes
place. Also write chemical equation for
the reaction.
[CBSE OD, Term 2, Set 1, 2016]

Short Answer Type Questions-II (3 marks each)

Q. 1. 3 mL of ethanol is taken in a test tube

and warmed gently in a water bath.
A 5% solution of alkaline potassium
permanganate is added first drop by
drop to this solution, then in excess.
(i) How is 5% solution of KMnO4
prepared?
(ii) State the role of alkaline potassium
permanganate in this reaction. What .
happens on adding it in excess?
(iii) Write chemical equation of this Q. 3. What is a homologous series of carbon
reaction. [CBSE Delhi, Set 1, 2020] compounds? Give an example and list
its three characteristics.
[CBSE OD, Set 1, 2019]

Q. 2. (a) Draw the structures for (i) ethanol,

(ii) ethanoic acid.
(b) Why is the conversion of ethanol
to ethanoic acid considered an
oxidation reaction? Write the
oxidising agent used in the reaction
involved. [CBSE Delhi, Set 3, 2020]

Q. 4. Which compounds are called (i) alkanes,

(ii) alkenes and (iii) alkynes? C4H10
belongs to which of these? Draw two
structural isomers of this compound.
[CBSE OD, Set 2, 2019]
Q. 5. (a) Why are most carbon compounds
poor conductors of electricity?
(b) Write the name and structure of a
saturated compound in which the
carbon atoms are arranged in a
ring. Give the number of single
bondspresent in this compound.
[CBSE, 2018]

Ans.

Q. 6. Write the structural formula of ethanol.

What happens when it is heated with
excess of conc. H2SO4 at 443 K? Write Q. 9. Explain esterification reaction with the
the chemical equation for the reaction help of a chemical equation. Describe
stating the role of conc. H2SO4 in this an activity to show esterification.
reaction. [CBSE OD, Term 2, Set 2, 2017]
[CBSE OD, Term 2, Set 1, 2017]
Ans.

Q. 7. Distinguish between esterification and

saponification reaction with the help Q. 10. Two carbon compounds X and Y have
of the chemical equations for each. the molecular formula C4H8 and C5H12
State one use of each (i) esters, and (ii) respectively. Which one of these is most
saponification process. likely to show addition reaction? Justify
[CBSE OD, Term 2, Set 1, 2017] your answer. Also give the chemical
equation to explain the process of
addition reaction in this case.
Q. 8. What happens when (write chemical [CBSE Delhi, Term 2, Set 1, 2017]
equation in each case)
(a) ethanol is burnt in air?
(b) ethanol is heated with excess
conc. H2SO4 at 443 K?
(c) a piece of sodium is dropped
into ethanol?
[CBSE OD, Term 2, Set 2, 2017]
Q. 11. Complete the following chemical 
equations: Q. 15. The molecular formula of two carbon
(i) CH3COOC2H5  NaOH  compounds are C4H8 and C3H8. Which
(ii) CH3COOH  NaOH 
Conc. H2 SO4
(iii) C2H5 OH + CH3 COOH one of the two is most likely to show
[CBSE Delhi, Term 2, Set 1, 2017] addition reaction? Justify your answer.
Also give the chemical equation to
explain the process of addition reaction
in this case.
[CBSE Delhi, Term 2, Set 3, 2017]

Q. 12. Complete the following chemical

equations:
(i) CH3COOH + Na2CO3 
(ii) CH4 + O2 
(iii) 2C2H5OH + Na  Q. 16. Write the electronic configuration of two
[CBSE Delhi, Term 2, Set 2, 2017] elements X and Y whose atomic numbers
Q. 13. Two carbon compounds X and Y have are 20 and 17 respectively. Write the
the molecular formula C3H6 and C4H10 molecular formula of the compound
respectively. Which one of the two is formed when element X reacts with
most likely to show addition reaction? element Y. Draw electron-dot structure
Justify your answer. Also give the of the product and also state the nature
chemical equation to explain the process of the bond formed between both the
of addition reaction in this case. elements.[CBSE OD, Term 2, Set 3, 2017]
[CBSE Delhi, Term 2, Set 2, 2017] Ans.

Q. 14. Complete the following chemical

equations:
(i) C2H5OH + O2 
(ii) C2H5OH Conc.443H2KSO4
(iii) CH3COOH + NaHCO3 
[CBSE Delhi, Term 2, Set 3, 2017]
Q. 17. An aldehyde as well as a ketone can
be represented by the same molecular
formula, say C3H6O. Write their
structures and name them. State the
relation between the two in the language
of science.
[CBSE OD, Term 2, Set 1, 2016]
Ans.

Q. 20. When ethanol reacts with ethanoic

acid in the presence of conc. H2SO4, a
substance with fruity smell is produced.
Answer the following:
(i) State the class of compounds
Q. 18. On dropping a small piece of sodium in to which the fruity smelling
a test-tube containing carbon compound compounds belong. Write the
‘X’ with molecular formula C2H6O, a chemical equation for the reaction
brisk effervescence is observed and and write the chemical name of the
a gas ‘Y’ is produced. On bringing a product formed.
(ii) State the role of conc. H2SO4 in this
reaction.
[CBSE Delhi, Term 2, Set 1, 2016]
Ans.
burning splinter at the mouth of the
test-tube the gas evolved burns with
a pop sound. Identify ‘X’ and ‘Y’. Also
write the chemical equation for the
Q. 21. What is an oxidising agent? What
reaction. Write the name and structure
happens when an oxidising agent is
of the product formed, when you heat
added to propanol? Explain with the
‘X’ with excess conc. sulphuric acid.
help of a chemical equation.
[CBSE OD, Term 2, Set 2, 2016]
[CBSE Delhi, Term 2, Set 2, 2016]
Ans.

Q. 19. Write three different chemical reactions

showing the conversion of ethanoic acid
to sodium ethanoate. Write balanced
chemical equation in each case. Write the Q. 22. Name the compound formed when
name of the reactants and the products ethanol is heated in excess of conc.
other than ethanoic acid and sodium sulphuric acid at 443 K. Also write
ethanoate in each case. the chemical equation of the reaction
[CBSE OD, Term 2, Set 3, 2016] stating the role of conc. sulphuric acid
in it. What would happen if hydrogen
 is added to the product of this reaction
in the presence of catalysts such as Q. 25. What is meant by homologous series
palladium or nickel? of carbon compounds ? Classify the
[CBSE Delhi, Term 2, Set 3, 2016] following carbon compounds into two
Ans.
homologous series and name them.
C3H4, C3H6, C4H6, C4H8, C5H8, C5H10.
[CBSE OD, Term 2, Set 2, 2015]

Q. 23. Write chemical equation of the reaction

of ethanoic acid with the following: Q. 26. Write the name and general formula
(a) Sodium of a chain of hydrocarbons in which
an addition reaction with hydrogen is
(b) Sodium hydroxide
possible. State the essential condition
(c) Ethanol for an addition reaction stating this
Write the name of one main product of condition, write a chemical equation
each reaction. giving the name of the reactants and the
[CBSE OD, Term 2, Set 1, 2016] product of the reaction.
[CBSE OD, Term 2, Set 3, 2015]
Q. 24. List two tests for experimentally Q. 27. With the help of an example, explain the
distinguishing between an alcohol and process of hydrogenation. Mention the
a carboxylic acid and describe how these essential conditions for the reaction and
tests are performed. state the change in physical property
[CBSE OD, Term 2, Set 1, 2015] with the formation of the product.
[CBSE Delhi, Term 2, Set 1, 2015]
Q. 28. What is the difference between the Q. 30. Write the name and structural formula of the
molecules of soaps and detergents, compound obtained when ethanol is heated
chemically? Explain the cleansing action at 443 K with excess of conc. H2SO4. Also
of soaps. write the chemical equation for the reaction
[CBSE Delhi, Term 2, Set 1, 2015] starting the role of conc. H2SO4 in it.
[CBSE Delhi, Term 2, Set 3, 2015]

Q. 29. What is meant by isomers? Draw the Q. 31. When soap is scrubbed on a stain of curry
structures of two isomers of butane, C4H10. on a white cloth, why does it become
Explain why we cannot have isomers of reddish brown, and turns yellow again
first three members of alkane series. when the cloth is washed with plenty of
[CBSE Delhi, Term 2, Set 2, 2015] water? [CBSE Delhi, Term 1, Set 1, 2015]
Ans. Ans.
Q. 32. Draw the electron-dot structure for
ethyne. A mixture of ethyne and oxygen
is burnt for welding. In your opinion,
why cannot we use a mixture of ethyne
and air for this purpose?
[CBSE OD, Term 2, Set 1, 2015]
Ans.

Long Answer Type Questions (5 marks each)

Q. 1. (a) Compare soaps and detergents on (b) (b) Differentiate between addition
the basis of their composition and reaction and substitution reaction.
cleansing action in hard water. Give one example of each.
[CBSE OD, Set 2, 2020]
Q. 2. (a) Carry out the following conversions:
(i) Ethanol to Ethene

(ii)Ethanol to Ethanoic acid

 (i) poor conductors of electricity? and
(ii) have low melting and boiling
points? What happens when this

compound burns in oxygen?
Q. 3. Write the chemical formula and name [CBSE Delhi, Set 1, 2019]
of the compound which is the active Ans.
ingredient of all alcoholic drinks. List Q. 5. (a) State the reason why carbon can
its two uses. Write chemical equation neither form C4+ cations nor C4–
and name of the product formed when anions, but forms covalent bonds.
this compound reacts with:
(i) sodium metal
(ii) hot concentrated sulphuric acid
[CBSE Delhi, Set 1, 2019]
Ans.
Also state reasons to explain why
covalent compounds
Q. 4. What is methane? Draw its electron (i) are bad conductors of electricity.
dot structure. Name the type of bonds (ii) have low melting and boiling
formed in this compound. Why are such points.
compounds: (b) Write the structural formula of
benzene, C6H6. [CBSE, 2019]

Q. 6. Why are certain compounds called

hydrocarbons? Write the general Q. 8. A carbon compound ‘P’ on heating
formula for homologous series of with excess conc. H2SO4 forms another
alkanes, alkenes and alkynes and also carbon compound ‘Q’ which on
draw the structure of the first member addition of hydrogen in the presence of
of each series. Write the name of the nickel catalyst forms a saturated carbon
reaction that converts alkenes into compound ‘R’. One molecule of ‘R’ on
alkanes and also write a chemical combustion forms two molecules of
equation to show the necessary carbon dioxide and three molecules of
conditions for the reactionto occur. water. Identify P, Q and R and write
[CBSE OD, Term 2, Set 1, chemical equations for the reactions
2017] involved.
Q. 7. Soaps and detergents are both types [CBSE OD, Term 2, Set 1, 2016]
of salts. State the difference between Q. 9. (a) Give a chemical test to distinguish
the two. Write the mechanism of the between saturated and unsaturated
cleansing action of soaps. Why do soaps hydrocarbon.
not form lather (foam) with hard water? (b) Name the products formed when
Mention any two problems that arise due ethane burns in air. Write the
to the use of detergents instead of soaps. balanced chemical equation for
[CBSE Delhi, Term 2, Set 1, 2017]
 the reaction showing the types of
energies liberated. Q. 11. Explain why carbon forms compounds
(c) Why is reaction between methane mainly by covalent bond. Explain in
and chlorine in the presence of brief two main reasons for carbon
sunlight considered a substitution forming a large number of compounds.
reaction? Why does carbon form strong bonds
[CBSE Delhi, Term 2, Set 1, 2016] with most other elements?
[CBSE Delhi, Term 2, Set 1, 2015]
Ans.

Q. 10. Both soap and detergent are some type

of salts. What is the difference between
them? Describe in brief the cleansing
action of soap. Why do soaps not form
lather in hard water? List two problems
that arise due to the use of detergents
instead of soaps.
[CBSE OD, Term 2, Set 1, 2015]