CBSE Class 10 Science Carbon and its compound Sure Shot Questions A

CBSE Class 10 Science Chapter 4 Carbon and its compound MCQs

Question. Which of the following organic compounds does not have the same chemical properties as methanol?
(a) C₂H₆O
(b) C₅H₁₀O
(c) C₄H₁₀O
(d) C₇H₁₆O
Answer. B

Question. Which of the following is correct about the structure of diamond?
(a) Carbon atoms are held together by single covalent bonds.
(b) Electrons move freely through the structure.
(c) Layers of atoms slide easily over each other.
(d) Carbon atoms conduct electricity in the molten state.
Answer. A

Question. Z has the same boiling point as n-butane.
(a) 1, 2 and 3
(b) 2 and 4
(c) 1 and 4
(d) 1, 3 and 4
Answer. A

Question. How many structural isomers are possible for pentane (C₅H₁₂)?
(a) 1
(b) 4
(c) 2
(d) 3
Answer. D

Question. In C₆H₁₄ the number of possible isomers is
(a) 3
(b) 6
(c) 4
(d) 5
Answer. D

Question. __________ is widely used as a fuel and is a major component of bio-gas and CNG. It is also one of the simplest compounds formed by carbon.
(a) Ethane
(b) Propane
(c) Carbon dioxide
(d) Methane
Answer. D

Question. Which of the following compounds has a triple bond?
(a) C₂H₄
(b) C₃H₄
(c) C₃H₈
(d) C₄H₁₀
Answer. B

Question. Which of the following statements is correct?
(a) Most organic compounds are ionic compounds.
(b) Ethane and ethene belong to the same homologous series.
(c) Propene contains three hydrogen atoms per molecule.
(d) Chloroethane contains two carbon atoms per molecule.
Answer. D

Question. All the members of homologous series of alkynes have the general formula
(a) C_nH_2n
(b) C_nH_{2n + 2}
(c) C_nH_{2n – 2}
(d) C_nH_{2n – 4}
Answer. C

Question. Three hydrocarbons X, Y and Z are shown below :
X : CH₃CH₂CH₂CH₂CH₃
Y : CH₃ —C ≡C —CH₂CH₃
Z : CH₃CH₂— CH ≡CH —CH₃
Identify the incorrect statements about these three hydrocarbons.
I. X and Y both differ by a CH₂ unit.
II. X and Z have the same boiling point.
III. All have different general formulae.
IV. Y and Z have different molecular masses.
(a) I and II
(b) II and III
(c) I and IV
(d) All the statements are incorrect
Answer. A

Question. Which of the following statements is correct about a substance that has a giant covalent structure?
(a) All its ions are arranged in a giant three dimensional lattice.
(b) A large amount of energy is needed to break down the lattice structure.
(c) It conducts electricity in the molten state.
(d) It dissolves in water but is more soluble in organic solvents.
Answer. B

Question. The general formula of cycloalkanes is
(a) C_nH_{2n + 2}
(b) C_nH_{2n – 2}
(c) C_nH_{2n – 1}
(d) C_nH_2n
Answer. D

Question. Which of the following exists as a simple triatomic molecule?
(a) Argon
(b) Fluorine
(c) Nitrogen
(d) Ozone
Answer. D

Question. Which of the following molecules has all its atoms joined together by double covalent bonds?
(a) Methane
(b) Water
(c) Carbon dioxide
(d) Nitrogen trichloride
Answer. C

Question. Which of the following is not a characteristic of members of a homologous series?
(a) They possess varying chemical properties.
(b) Their physical properties vary in regular and predictable manner.
(c) Their formulae fit the general molecular formula.
(d) Adjacent members differ by one carbon and two hydrogen atoms.
Answer. A

Question. Which covalent molecule contains the structure where the central atom is bonded to four other atoms by covalent bonds?
1. Diamond   2. Graphite
3. Methane   4. Silicon dioxide
(a) 1 and 2
(b) 2 and 4
(c) 3 and 4
(d) 1, 3 and 4
Answer. D

Question. Which of the following represent saturated hydrocarbons?
1. CH(CH₃)₃
2. CH₂CHCH₃
3. CH₃CH(CH₃)CH₂CH₃
4. (CH₃)₂CCHCH₃
(a) 1 and 3
(b) 2 and 4
(c) 1, 2 and 3
(d) 1, 2, 3 and 4
Answer. A

Question. Which of the following has shortest carboncarbon bond length?
(a) C₂H₂
(b) C₂H₄
(c) C₂H₆
(d) C₆H₆
Answer. A

Question. Which type of bond is present between carbon-carbon atoms in acetylene?
(a) Single covalent bond
(b) Double covalent bond
(c) Triple covalent bond
(d) Electrovalent bond
Answer. C

Question. Number of free electron(s) in each carbon atom in graphite is/are
(a) two
(b) four
(c) one
(d) three.
Answer. C

Question. Which of the following statements is not correct?
(a) A common functional group is present in different members of a homologous series.
(b) Two consecutive members of a homologous series differ by a –CH3 group.
(c) The members of a homologous series can be represented by one general formula.
(d) Different members of a homologous series have similar chemical properties.
Answer. B

Question. Identify the correct statements.
(i) As the molecular mass increases in any homologous series, a gradation in physical properties is seen.
(ii) The melting and boiling points decrease with increasing molecular mass.
(iii) Other physical properties such as solubility in a particular solvent decreases with increasing molecular mass.
(iv) The chemical properties, which are determined solely by the functional group, remain similar in a homologous series.
(a) (ii) and (iii)
(b) (ii) and (iv)
(c) (i), (iii) and (iv)
(d) All are correct
Answer. C

CBSE Class 10 Science Chapter 4 Carbon and its compound Assertion and Reason

For question numbers 56-70, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
(a) Both assertion and reason are true, and reason is correct explanation of the assertion.
(b) Both assertion and reason are true, but reason is not the correct explanation of the assertion.
(c) Assertion is true, but reason is false.
(d) Assertion is false, but reason is true.

Question. Assertion : In alkanes, alkenes and alkynes the valency of carbon is always four.
Reason : All hydrocarbons except alkanes contain double bonds.
Answer. C

Question. Assertion : Carbon possesses property of catenation.
Reason : Carbon atoms form double as well as triple bonds during catenation.
Answer. B

Question. Assertion : Ethanol is first member of the alcohol homologous series.
Reason : A homologous series can be represented by a general formula.
Answer. D

Question. Assertion : Diamond is the hardest natural known substance.
Reason : Diamond is used for cutting marble, granite and glass.
Answer. B

Question. Assertion : Diamond is not a good conductor of electricity.
Reason : It has no free electrons.
Answer. A

Question. Assertion : Two members of a homologous series have similar chemical properties.
Reason : Propane and butane are members of same homologous series.
Answer. B

Question. Assertion : Saturated hydrocarbons are chemically less reactive.
Reason : All the valencies of carbon atom are satisfied by single covalent bonds.
Answer. A

Question. Assertion : Covalent compounds are generally poor conductor of electricity.
Reason : They consist of molecules and not ions which can transfer charge.
Answer. A

Question. Assertion : Graphite is a good conductor of electricity.
Reason : It has one free valence electron.
Answer. A

Question. Assertion : The functional group present in alcohols is –OH.
Reason : It is the same group as present in water, hence water and alcohol have similar properties.
Answer. C

Question. Assertion : Diamond and graphite do not have the same crystal structure.
Reason : Diamond is crystalline while graphite is amorphous.
Answer. C

Question. Assertion : Carbon and its compounds can be used as fuels.
Reason : They are highly inflammable and have high calorific value.
Answer. A

Question. Assertion : Olefins have the general formula C_nH_2n+1.
Reason : There is atleast one double bond between two carbon atoms in their molecules.
Answer. D

Question. Assertion : Graphite is soft and slippery to touch.
Reason : Graphite has sheet like layered structure.
Answer. A

Question. Assertion : Both aldehydes and ketones contain carbonyl group.
Reason : In aldehydes, the functional group is attached to atleast one hydrogen atom.
Answer. B

CBSE Class 10 Science Chapter 4 Carbon and its compound Case Based MCQs

Case I : Read the passage given below and answer the following questions.

An organic molecule has the following structure :

Question. To which homologous series does this molecule belong?
(a) Aldehydes
(b) Ketones
(c) Alcohols
(d) Alkanes
Answer. C

Question. What is the general formula of this homologous series?
(a) C_nH_2n + 1OH
(b) C_nH_2n + 2
(c) C_nH_2nO
(d) C_nH_2n + 1CHO
Answer. A

Question.  Which is the next member of this series?
(a) C₄H₉OH
(b) C₃H₇OH
(c) C₅H₁₁OH
(d) C₆H₁₃OH
Answer. C

Question. Which is the third member of this series?
(a) C₃H₇OH
(b) C₄H₉OH
(c) C₂H₅OH
(d) CH₃OH
Answer. A

Question. Which is the second member of this series?
(a) Ethanol
(b) Methanol
(c) Propanol
(d) Butanol
Answer. A

Case II : Read the passage given below and answer the following questions.

When an element exists in two or more different forms in the same physical state, these different forms are called allotropes and the phenomenon is known as allotropy. Allotropes have similar chemical properties but they differ in their physical properties. Carbon exists in crystalline and amorphous forms. In crystalline form, it occurs as diamond, graphite and fullerenes. Diamond is a colourless, transparent substance having extraordinary brilliance. It is the hardest natural substance known. It is used for cutting marble, granite and glass. Graphite is a greyishblack, opaque substance. It is lighter than diamond i.e., it has lower density. It has sheet like structure having hexagonal layers. One layer slides over the other layer which makes it soft to touch. It is the reason that graphite is used as a lubricant.

Question. Substance X is a moderate conductor of electricity. Substance X has the structure shown below :
Which statements about substance X are correct?
(I) It is a covalent compound.
(II) It has a giant molecular structure.
(III)It has the same structure as graphite.
(IV) It has the same structure as diamond.
(a) (I) and (III)
(b) (II) and (III)
(c) (II) and (IV)
(d) (I), (II) and (IV)
Answer. C

Question. Which of the following is correct about the structure of diamond?
(a) Carbon atoms are held together by single covalent bonds.
(b) Electrons move freely through the structure.
(c) Layers of atoms slide easily over each other.
(d) Carbon atoms conduct electricity in the molten state.
Answer. A

Question. Which three allotropes of carbon, do the given figures represent?

Answer. D

Question. Identify the incorrect statement(s).
(I) Diamond is the hardest substance known while graphite is smooth and slippery.
(II) Diamond is made up of billions of carbon atoms. Each carbon atom is bonded to four other carbon atoms in a tetrahedral manner to form a giant lattice. All carbon atoms are bonded by strong covalent bonds.
(III) Graphite is a poor conductor of electricity unlike other non-metals.
(IV) Graphite has a giant covalent structure that is made up of layers of carbon atoms.
In each layer, each carbon atom is bonded to three other carbon atoms to form hexagonal rings of carbon atoms.
(a) (I) and (III)
(b) Only (III)
(c) (II) and (IV)
(d) (I), (II) and (IV)
Answer. B

Question. Structures of two different forms of carbon are given below :

Identify the two forms (I and II respectively) and how are they related to each other?
(a) Diamond, Graphite, Isotopes of carbon
(b) Graphite, Diamond, Allotropes of carbon
(c) C¹², C¹⁴, Allotropes of carbon
(d) C¹⁴, C¹², Isotopes of carbon
Answer. B

CARBON AND ITS COMPOUND

1. Which of the following is not a saturated hydrocarbon ?

i) Cyclohexane.

ii) Benzene.

iii) Butane

iv) isobutene

2. The bond between two identical non metallic atom has a pair of electron ?

i) un equally shared between two atoms.

ii) Transferred completely from one atom to another.

iii) With identical spins

iv) Unequally shared between them.

3. Covalent compounds are generally

i) Soluble in water

ii) Insoluble in water

iii) Ionize in water

iv) Hydrolyse in water

4. Propane with the molecular formula C₃H₈ has

i) 7covalent bonds

ii) 8 covalent bonds

iii) 9 covalent bonds

iv) 10 Covalent bonds.

5. A hydrocarbon reacts with ammonical cuprous chloride solution to form a red precipitate .The hydrocarbon is

i)ethane

ii)ethene

iii)butane

iv)1-propyne

6. Which of the following substance is added to denature Ethanol ?

i)methanol               ii)pyridine

iii)copper sulphate    iv)all of them

7. Which of the following is not an allotropic form of carbon

i)fluorine           ii)fullerene

iii)diamond        iv)graphite

8. Which of the following represents the correct decreasing order of hydrogen atoms ?
i)alkanes , alkenes , alkynes
ii)alkanes , alkaynes , alkenes
iii)alkenes , alkynes , alkanes
iv)alkynes , alkanes , alkenes

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