Q60 of 312 Page 224

A solid element X has four electrons in the outermost shell of its atom. An allotrope Y of this element is used as a dry lubricant in machinery and also in making pencil leads.

(a) What is element X?


(b) Name the allotrope Y?


(c) State whether allotrope Y is a good conductor or non-conductor of electricity.


(d) Name one use of allotrope Y (other than lubrication and pencil leads)


(e) Name two other allotropes of element X.

(a) Element X is carbon.

(b) Allotrope Y is graphite.


(c) Allotrope Y is a good conductor of electricity (due to the presence of free electron).


(d) Allotrope Y is used for making electrodes of cells.


(e) Diamond and Buckministerfullerence are allotropes of element X.



More from this chapter

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58 The number of isomers formed by the hydrocarbon with molecular formula C5H12 is: 59 The number of carbon atoms joined in a spherical molecule of buckministerfullerence is: 61 Two organic compounds A and B have the same molecular formula C6H12. Write the names and structural formulae:

(a) if A is cyclic compound


(b) if B is an open chain compound


(c) Which compound contains single bonds as well as a double bond?


(d) Which compound contains only single bonds?

 62 The solid element A exhibits the property of catenation. It is also present in the form of a gas B in the air which is utilized by plants in photosynthesis. An allotrope C of this element is used in glass cutters.

(a) What is element A?


(b) What is the gas B?


(c) Name the allotrope C.


(d) State another use of allotrope C (other than in glass cutters)


(e) Name another allotrope of element A which exists as spherical molecules.


(f) Name a yet another allotrope of element A which conducts electricity.