CBSE Class 10 Science Carbon and its Compounds MCQs Set A

Question : C₃H₈ belongs to the homologous series of
(a) Alkynes
(b) Alkenes
(c) Alkanes
(d) Cyclo alkanes

Answer :  C

Question : A hydrocarbon should have a minimum of how many carbon atoms to show isomerism?
(a) Three
(b) Four
(c) Five
(d) Six

Answer :  B

Question : Ethane, with the molecular formula C2H6 has
(a) 6 covalent bonds.
(b) 7 covalent bonds.
(c) 8 covalent bonds.
(d) 9 covalent bonds.
Answer : B

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.
Answer : B

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

Question : Which one of the given is an unsaturated hydrocarbon?
(a) Acetylene
(b) Butane
(c) Propane
(d) Decane

Answer :  A

Question : Which is denatured spirit?
(a) ethanol only
(b) ethanol and methanol (50%)
(c) ethanol and methanol (5%)
(d) methanol only

Answer :  C 

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
(c) Displacement reaction
(d) Oxidation reaction

Answer :  A

Question : Artificial flavour for orange is obtained from
(a) amyl acetate
(b) isoamyl valerate
(c) methyl butyrate
(d) octyl acetate

Answer :  D

Question : The odour of acetic acid resembles that of
(a) Rose
(b) Burning Plastic
(c) Vinegar
(d) Kerosene

Answer :  C

Question : Ethanol reacts with Na metal to form
(a) CH₃ONa + H₂
(b) C₂H₅ONa + H₂
(c) CH₃COONa + H₂
(d) CH₃C00H + H₂O

Answer :  B

Question : IUPAC name of first member of homologous series of ketones is
(a) Ethanone
(b) methanone
(c) Propanone
(d) Butanone

Answer :  C

Question : Covalent compounds
(a) (a) have high melting and boiling point
(b) are mostly soluble in water
(c) are formed between atoms of metals and non-metals
(d) are formed by the sharing of electrons in the bonding atoms.

Answer :  D

Question : Rectified spirit is
(a) 50% ethanol
(b) 80% ethanol
(c) 95% ethanol
(d) 40 to 50% ethanol

Answer :  C 

Question : Why does carbon form compounds mainly by covalent bonding?
(a) There are four electrons in the outermost shell of carbon.
(b) It requires large amount of energy to form C4+ or C4–
(c) It shares its valence electrons to complete its octet.
(d) All the above

Answer :  D

Question : The First Member Of Alkyne Homologous Series Is:
(a) Ethyne
(b) Ethene
(c) Propyne
(d) Methane

Answer :  A

Question : The first member of the alkyne homologous series is
(a) propyne
(b) ethyne
(c) methane

Answer :  B

Question : Methane is ______
(a) Unsaturated compound
(b) nitrogen compound
(c) Saturated compound
(d) Ionic compound

Answer :  C

Question : The isomeric pair is
(a) Ethane and propane
(b) Propane and butane
(c) Ethane and ethane
(d) Butane and 2-methylpropane

Answer :  D

Question : From where can we get ethanol?
(a) Grapes
(b) Beet root
(c) Sugarcane
(d) Orange

Answer :  C

Question : The substance not responsible for the hardness of water is
(a) Sodium nitrate
(b) Calcium hydrogen carbonate
(c) Calcium carbonate Magnesium carbonate

Answer :  A

Question : Ethanol on oxidation gives
(a) Ethane
(b) Formalin
(c) Ethanoic acid
(d) Methane

Answer :  C

Question : Which of the given can be used for the denaturation of ethyl alcohol?
(a) Methyl alcohol
(b) Pyridines
(c) Copper sulphate
(d) All of these

Answer :  D

Question : Read The Following Sentences Carefully, And Choose The Incorrect One:
(a) Graphite is non-volatile, so, it can-not be used for lubricating.
(b) Graphite is used for making carbon electrodes or graphite electrodes in dry cells and electric arcs.
(c) Diamonds can be made artificially by subjecting pure carbon to very high pressure and temperature.
(d) Diamond “dies” are used for drawing thin wires like the tungsten filament of an electric bul(b)

Answer :  A

Question : Butanone is a four carbon compound with functional group:
(a) carboxylic acid
(b) alcohol
(c) ketone
(d) aldehyde

Answer :  C

Question : Compounds with _______ molecular formula with different structures called _______
(a) Same, structural isomerism
(b) Different, structural isomerism
(c) Same, monomeric structures
(d) Different, monomeric structures

Answer :  A

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

Answer :  B

Question : A molecule of ammonia (NH₃) has
(a) Only single bonds
(b) Only double bonds
(c) Only triple bonds
(d) Two double bonds and one single bond

Answer :  A

Which allotrope of carbon is in the form of the geodesic globe?
(a) Graphite
(b) Diamond
(c) Fullerene
(d) Carbon nanotube

Answer :  C

Question. The diagram given below shows the electron arrangement of the valence electrons in a molecule of compound PQ3. Which of the following pairs of elements could be P and Q ? 

          P               Q
(a) Argon           Neon
(b) Phosphorus  Hydrogen
(c) Nitrogen      Chlorine
(d) Sulphur      Oxygen

Answer : C

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

Answer : C

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) CnH2n – 4

Answer : C

Question. The structures of three hydrocarbons, X, Y and Z are shown below: 


Which of the statements about X, Y and Z are correct?
1. X and Y are isomers.
2. X and Y have the same percentage composition by mass.
3. Y is the isomer of alkane having formula, C₅H₁₂.
4. 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. 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. 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

Answer : C

Question. A functional group mainly determines the
(a) Physical properties
(b) Chemical properties
(c) Both
(d) None of these

Answer : B

Question. 100% pure ethanol is called
(a) Rectified spirit
(b) Absolute alcohol
(c) Denatured alcohol
(d) Power alcohol

Answer : B