4. Carbon and its Compounds

SEBA Class 10 Science Chapter 4 Carbon and its Compounds

4. Carbon and its Compounds

SEBA Class 10 Science Chapter 4. Carbon and its Compounds Multiple Choice Questions answers :

Question : Ethane, with the molecular formula has
(a) 6 covalent bonds.
(b) 7 covalent bonds.
(c) 8 covalent bonds.
(d) 9 covalent bonds.

Solution: (b) 7 covalent bonds.
Question : Butanone is a four-carbon compound with the functional group
(a) carboxylic acid.
(b) aldehyde.
(c) ketone.
(d) alcohol.

Solution: (c) ketone.
Question : While cooking, if the bottom of the vessel is getting blackened on the outside, it means that
(a) the food is not cooked completely.
(b) the fuel is not burning completely.
(c) the fuel is wet.
(d) the fuel is burning completely.

Solution: (b) the fuel is not burning completely.

Question: A molecule of propane has : [2015]

(a) 10 covalent bonds (b) 9 covalent bonds (c) 8 covalent bonds (d) 11 covalent bonds

Answer : (a) 10 covalent bonds

Question : When combustion takes place in insufficient air (oxygen) gas produces . [SEBA 2023]

Answer : incomplete combustion

[When combustion takes place in insufficient air (oxygen), incomplete combustion occurs, and carbon monoxide (CO) gas is produced. Incomplete combustion happens when there is not enough oxygen to completely oxidize the fuel (such as hydrocarbons). ]

Question : The hydrocarbon which is the major component of Compressed Natural Gas (CNG) is .[SEBA 2023]

Answer : methane

[ The hydrocarbon which is the major component of Compressed Natural Gas (CNG) is methane.]

Question : Carbon exists in the atmosphere in the form of

(a) carbon monoxide only

(b) carbon monoxide in traces and carbon dioxide

(d) coal

Answer : (c) carbon dioxide only

[ Carbon exists in the atmosphere primarily in the form of carbon dioxide (). ]

Question : Which of the following statements are usually correct for carbon compounds? These

(i) are good conductors of electricity

(ii) are poor conductors of electricity

(iii) have strong forces of attraction between their molecules

(iv) do not have strong forces of attraction between their molecules

(a) (i) and (iii) (b) (ii) and (iii)

Answer : (d) (ii) and (iv)

[ Carbon compounds are generally poor conductors of electricity (ii) and do not have strong forces of attraction between their molecules (iv).]

Question : A molecule of ammonia () has

(a) only single bonds

(b) only double bonds

(d) two double bonds and one single bond

Answer : (a) only single bonds .

[ A molecule of ammonia () has only single bonds. ]

Question : Buckminsterfullerene is an allotropic form of

(a) phosphorus

(b) sulphur

(d) tin

Answer : (c) carbon

[ Buckminsterfullerene is an allotropic form of carbon. ]

Question : Which of the following are correct structural isomers of butane?

(a) (i) and (iii) (b) (ii) and (iv) (c) (i) and (ii) (d) (iii) and (iv)

Answer : (c) (i) and (ii)

Question :

In the above given reaction, alkaline acts as

(a) reducing agent

(b) oxidising agent

(d) dehydrating agent

Answer : (b) oxidising agent

[ In the given reaction:

Alkaline is acting as an oxidizing agent. ]

Question : Oils on treating with hydrogen in the presence of palladium or nickel catalyst form fats. This is an example of

(a) Addition reaction

(b) Substitution reaction

(d) Oxidation reaction

Answer : (a) Addition reaction

[ The process described, where oils are treated with hydrogen in the presence of a catalyst (palladium or nickel) to form fats, is an example of an addition reaction. ]

Question : In which of the following compounds, - OH is the functional group?

(a) Butanone

(b) Butanol

(d) Butanal

Answer : (b) Butanol

[ In the given options, the functional group - OH is present in the compound Butanol.]

Question : The soap molecule has a

(a) hydrophilic head and a hydrophobic tail

(b) hydrophobic head and a hydrophilic tail

(d) hydrophilic head and a hydrophilic tail

Answer : (a) hydrophilic head and a hydrophobic tail

[ The soap molecule has a hydrophilic (water-attracting) head and a hydrophobic (water-repelling) tail. ]

Question : Which of the following is the correct representation of electron dot structure of nitrogen?

Answer : (d)

Question : Structural formula of ethyne is

Answer : (a)

Question : Identify the unsaturated compounds from the following

(i) Propane

(ii) Propene

(iii) Propyne

(iv) Chloropropane

(a) (i) and (ii) (b) (ii) and (iv)

Answer : (d) (ii) and (iii).

[ The unsaturated compounds are (ii) Propene and (iii) Propyne. ]

Question : Chlorine reacts with saturated hydrocarbons at room temperature in the

(a) absence of sunlight

(b) presence of sunlight

(d) presence of hydrochloric acid

Answer : (b) presence of sunlight.

[ Chlorine reacts with saturated hydrocarbons at room temperature in the presence of sunlight. The reaction is a substitution reaction known as free radical halogenation. ]

Question : In the soap micelles

(a) the ionic end of soap is on the surface of the cluster while the carbon chain is in the interior of the cluster.

(b) ionic end of soap is in the interior of the cluster and the carbon chain is out of the cluster.

(d) both ionic end and carbon chain are on the exterior of the cluster

Answer : (a) The ionic end of soap is on the surface of the cluster while the carbon chain is in the interior of the cluster.

[In the formation of micelles, the hydrophobic tails (carbon chain) of soap molecules cluster in the interior, away from water, while the hydrophilic heads (ionic end) remain on the surface, interacting with water. ]

Question : Pentane has the molecular formula . It has

(a) 5 covalent bonds

(b) 12 covalent bonds

(d) 17 covalent bonds

Answer : (c) 16 covalent bonds.

Question : Structural formula of benzene is

Answer : (c)

Question : Ethanol reacts with sodium and forms two products. These are

(a) sodium ethanoate and hydrogen

(b) sodium ethanoate and oxygen

(d) sodium ethoxide and oxygen

Answer : (c) Sodium ethoxide

[ When ethanol () reacts with sodium (Na), it undergoes a reaction known as alcoholysis. The products of this reaction are sodium ethoxide () and hydrogen gas (). ]

Question : The correct structural formula of butanoic acid is

Answer : (d)

Question : Vinegar is a solution of

(a) 50% – 60% acetic acid in alcohol

(b) 5% – 8% acetic acid in alcohol

(d) 50% – 60% acetic acid in water

Answer : (c) 5% – 8% acetic acid in water

[ Vinegar is a solution of 5% – 8% acetic acid in water. ]

Question : Mineral acids are stronger acids than carboxylic acids because

(i) mineral acids are completely ionised

(ii) carboxylic acids are completely ionised

(iii) mineral acids are partially ionised

(iv) carboxylic acids are partially ionised

(a) (i) and (iv) (b) (ii) and (iii)

Answer : (a) (i) and (iv).

[ Mineral acids are stronger acids than carboxylic acids because : (i) Mineral acids are completely ionized. (iv) Carboxylic acids are partially ionized. ]

Question : Carbon forms four covalent bonds by sharing its four valence electrons with four univalent atoms, e.g. hydrogen. After the formation of four bonds, carbon attains the electronic configuration of

(a) helium

(b) neon

(d) krypton

Answer : (c) Argon

[ Carbon forms four covalent bonds by sharing its four valence electrons with four univalent atoms, typically hydrogen. After the formation of four bonds, carbon attains the electronic configuration of argon .

Question : The correct electron dot structure of a water molecule is

Answer : (c)

Question : Which of the following is not a straight chain hydrocarbon?

Answer : (d)

Question : Which among the following are unsaturated hydrocarbons?

(a) (i) and (iii) (b) (ii) and (iii)

Answer : (c) (ii) and (iv)

Question : Which of the following does not belong to the same homologous series?

(a)

(b)

(c)

(d)

Answer : (d) - Butene

[ The homologous series is a group of organic compounds that have the same functional group and share a similar chemical properties and successive members differ by -CH2-.

The reason is that it is an alkene (contains a double bond), while the others are alkanes (contain only single bonds). ]

Question : The name of the compound is

(a) Propanal

(b) Propanone

(d) Ethanal

Answer : (a) Propanal

Question : The heteroatoms present in are

(i) oxygen

(ii) carbon

(iii) hydrogen

(iv) chlorine

(a) (i) and (ii) (b) (ii) and (iii)

Answer : (d) (i) and (iv).

[ The heteroatoms present in the given molecule are: (i) Oxygen (iv) Chlorine ]

Question : Which of the following represents saponification reaction?

(a)

(b)

(c)

(d)

Answer : (d)

Question : The first member of alkyne homologous series is

(a) ethyne

(b) ethene

(d) methane

Answer : (a) ethyne .