(i)Explain the anamolous behaviour of carbon. (ii)give reasons for: -> graphite is used as a lubricant ->Aluminium alloys are used to make aircraft body -> Diamond is used as an abrasive Plz give the answers.

Asked by GARIMA SRIVASTAVA | 4th Mar, 2011, 02:51: AM

Expert Answer:

Dear Student
 
(i) Carbon is found differ in many properties from the rest of the members of group 14. This is because of the following : (i) Its smallest size (ii) Its high electronegativity (iii) Its property to catenate (iv) Absence of d-orbitals in it.

The melting and boiling points of carbon are very high as compared to the rest to the members of the family. Carbon in its diamond form is one of the hardest substance known.  It has maximum tendency to show catenation. Carbon has high tendency to form Pπ– Pπ multiple bonds with other elements like nitrogen, oxygen, sulphur etc. Other members of the family form Pπ– dπ bonds and that also to a lesser extent. CO2 is a gas while the dioxides of all other members are solids.

(ii) The graphite is made up of layers and with a solvent absorbed in between these layers they can slip over each other, thus creating the lubricant effect. The diamond is amongst one of the hardest materials we know because the carbon is bound very well to each other. Thus it can cut other things and be a drill.

(iii) Aluminium has a high tensile strength and is very light in weight. It can also be alloyed with various metals such as Cu, Mn, Mg, Si, and Zn. It is very malleable and ductile. Therefore, it is used in making aircraft bodies.

(iv) As diamond is the hardest substance, it is used as abrasive.

We hope that clarifies your query.

Regards

Team

Topperlearning

Answered by  | 4th Mar, 2011, 12:40: PM

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