Carbon and its Compounds MCQ
1. Carbon exists in the atmosphere in the form of
(a) carbon monoxide only
(b) carbon monoxide in traces and carbon dioxide
(c) carbon dioxide only
(d) coal
Ans. (c) carbon dioxide only
2. 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)
(c) (i) and (iv)
(d) (ii) and (iv)
Ans. (d) (ii) and (iv)
Explanation: Organic compound are made of covalent bonds. These bonds have weaker forces of attraction. Covalent compounds are poor conductors of electricity.
3. 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
Ans. (a) Only single bonds
Explanation: The valency of nitrogen is 2 and that of hydrogen is one. Three atoms of hydrogen combine with 1 atom of nitrogen to make ammonia. Hence, there are three single bonds in ammonia.
4. Buckminsterfullerene is an allotropic form of
(a) phosphorus
(b) sulphur
(c) carbon
(d) tin
Ans. (c) Carbon
5. 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)
Ans. (c) (i) and (ii)
Explanation: Formula of butane is C4H10. Options (iii) and (iv) have 8 hydrogen atoms each, hence, they are incorrect.
6. In the given reaction, alkaline KMnO4 acts as
(a) reducing agent
(b) oxidising agent
(c) catalyst
(d) dehydrating agent
Ans. (b) Oxidising agent
Explanation: Two hydrogen atoms are replaced by an atom of oxygen in this reaction. This shows oxidization of ethanol. Addition oxygen is being provided by potassium permanganate.
7. 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
Ans. (a) Addition reaction
Explanation: In this reaction, hydrogen is added to oil.
8. In which of the following compounds, — OH is the functional group?
(a) Butanone
(b) Butanol
(c) Butanoic acid
(d) Butanal
Ans. (b) Butanol
Explanation: Compounds with -OH as functional group have ‘ol’ as suffix.
9. The soap molecule has a
(a) hydrophilic head and a hydrophobic tail
(b) hydrophobic head and a hydrophilic tail
(c) hydrophobic head and a hydrophobic tail
(d) hydrophilic head and a hydrophilic tail
Ans. (a) Hydrophilic head and hydrophobic tail
Explanation: Oil and grease is trapped inside a micelle because of hydrophobic tail. Hydrophilic head makes the outer surface of micelle. Thus, a micelle is easily washed by water.
10. Which of the following is the correct representation of electron dot structure of nitrogen?
Ans. (d)
Explanation: In this structure, each nitrogen atom gets 8 electrons. This is not the case in other options.
11. Structural formula of ethyne is
Ans. (a)
Explanation: The formula of ethyne is C2H2.
12. Identify the unsaturated compounds from the following
(i) Propane
(ii) Propene
(iii) Propyne
(iv) Chloropropane
(a) (i) and (ii)
(b) (ii) and (iv)
(c) (iii) and (iv)
(d) (ii) and (iii)
Ans. (d) (ii) and (iii)
Explanation: Propene has one double bond, while propyne has one triple bond. Hence,
they are unsaturated compounds.
13. Chlorine reacts with saturated hydrocarbons at room temperature in the
(a) absence of sunlight
(b) presence of sunlight
(c) presence of water
(d) presence of hydrochloric acid
Ans. (b) Presence of sunlight
Explanation: Chlorine reacts with saturated hydrocarbons in the presence of sunlight and displaces hydrogen atoms one by one.
14. 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.
(c) both ionic end and carbon chain are in the interior of the cluster.
(d) both ionic end and carbon chain are on the exterior of the cluster.
Ans. (a) the ionic end of soap is on the surface of the cluster while the carbon chain is in the interior of the cluster.
