Question

Assertion :Diamond is insulator and graphite is conducting. Reason: $C$-atom is $s{p}^3$ hybridized in both.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is C Assertion is correct but Reason is incorrect

Graphite has planar hexagonal layers of carbon atoms (3 $s{p}^2$ hybridized carbon atoms) held together by weak van der Waal's forces.
As in graphite, 3 carbon-carbon covalent bonds are present and fourth electron forms layer by vander waals forces and since pi-electrons are free to move throughout the entire layers so graphite is a good conductor of electricity. Its conductivity increases with temperature.
In diamond, each carbon atom is linked tetrahedrally to four other carbon atoms by $s{p}^3$ bonds so it doesnt have frre electrons and diamond is insulator.