Get the MCQs for CBSE Class 10 Science Chapter 4 Carbon and its Compounds. All these questions are Provided and are given responses and their itemized clarification. Check the MCQs gave beneath to find out about the sort of inquiries to be posed in the CBSE Class10 Science Board Exam 2021-2022.
MCQs from CBSE Class 10 Science Chapter 4: Carbon and its Compounds
12. Carbon exists in the atmosphere in the form of: [NCERT Exemplar]
(a) Carbon monoxide only
(b) Carbon monoxide in traces and carbon dioxide
(C) Carbon dioxide only
(d) Coal
Ans. (c) Carbon dioxide only Explanation :
Carbon exists in the atmosphere in the form of carbon dioxide gas (CO2) in air (Only 0.03%) and in the earth crust it exists in the form of the minerals like carbonates. It also occurs in the form of fossil fuels, organic compounds, wood, cotton and wool, etc.
13. What is true about covalent compounds? They:
(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
Ans. (d) Are formed by the sharing of electrons in the bondinga toms.
Explanation :
Covalent compounds are held together by weak intermolecularf orces which fail to hold the compound bonded tightly. Thus, as mall amount of heat energy is capable of breaking these weaki ntermolecular forces, therefore, the melting and boiling points ofc ovalent compounds are low. Covalent compounds are non-polar inn ature which means they do not dissolve in water, instead make as eparate layer on the surface of water. Hence, Compounds havingc ovalent bonds are insoluble in water. Covalent compounds aref ormed by the sharing of electrons in the bonding atoms betweent wo non-metals.
14. Covalent compounds are __________ conductors of electricity.
(a) Good
(b) Bad
(c) Moderate
(d) None of them
Ans. (b) Bad.
Explanation :
Covalent compounds are bad conductors of electricity because theyd o not produce ions in solution.
15. Buckminster fullerene is an allotropic form of : [NCERT Exemplar]
(a) Phosphorus
(b) Sulphur
(c) Carbon
(d) Tin
Ans. (c) Carbon.
Explanation :
Buckminsterfullerene (C60) is an allotropic form of carbon. It has carbon atoms arranged in the form of football and due to theirr esemblance with football they are also known as Bucky balls.
16. Which of the following statements are correct for carbonc ompounds?
(i) Most carbon compounds are good conductors of electricity.
(ii) Most carbon compounds are poor conductors of electricity.
(iii) Force of attraction between molecules of carbon compounds is not very strong.
(iv) Force of attraction between molecules of carbon compounds is very strong.
(a) (ii) and (iv)
(b) (ii) and (iii)
(b) (i) and (iv)
(d) (i) and (iii)
Ans. (b) (ii) and (iii)
Explanation :
Most carbon compounds are poor conductors of electricity because they are formed by the sharing of electrons and therefore they do not have free electrons. Current results from motion of electrons or ions. On dissolving them in water they do not form ions. So, they are generally poor conductors of electricity. Force of attraction between molecules of carbon compounds is not very strongb ecause they form covalent bond by sharing their valence electron in order to attain stable electronic gas configuration.
17. Which of the following statements are usually correct for carbon compounds ? These :
[NCERT Exemplar]
(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 :
Carbon compounds do not have strong forces of attraction betweentheir molecules because they are bonded to each other through covalent bonds which is weaker than ionic bond. They are poor conductors of electricity because of the absence of free ions.
18. How many number of carbon atoms are joined in a spherical molecule of Buckminsterfullerene?
(a) 30
(b) 60
(b) 90
(d) 120
Ans. (b) 60
Explanation :
Buckminsterfullerene is the first discovered fullerene. It is a molecule of carbon in the form of a soccer ball consisting of 60 C- atoms and is having the formula C-60. These 60 carbon atoms are joined together by strong covalent bonds and are arranged in interlocking hexagonal and pentagonal rings of carbon atom.
19. The allotrope of carbon which is a good conductor of heat and electricity is
(a) Diamond
(b) Graphite
(b) Charcoal
(d) None of these
Ans. (b) Graphite
Explanation :The allotrope of carbon which is a good conductor of heat and electricity is graphite. This is because, in its planar structure it has three electrons which are covalently bonded and fourth electron is free to move along the layers from one carbon atom to the next when connected to an external battery.
20. In diamond, each carbon atom is bonded to four other carbon atoms to form:
(a) A hexagonal array
(b) A rigid three-dimensional structure
(c) A structure in the shape of a football
(d) A structure of a ring
Ans. (b) A rigid three-dimensional structure
Explanation : In diamond, each carbon atom is bonded to four other carbon atoms tetrahedrally to form a rigid three-dimensional structure. This rigid three dimensional structure of carbon is responsible for the hardness and rigidity of diamond.
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