With respect to graphite and diamond, which of the statement(s) given below is (are) correct ?
(A) Graphite is harder than diamond.
(B) Graphite has higher electrical conductivity than diamond.
(C) Graphite has higher thermal conductivity than diamond.
(D) Graphite has higher C-C bond order than diamond.
(A) Graphite is harder than diamond.
(B) Graphite has higher electrical conductivity than diamond.
(C) Graphite has higher thermal conductivity than diamond.
(D) Graphite has higher C-C bond order than diamond.
- (A)Graphite is harder than diamond.
- (B)Graphite has higher electrical conductivity than diamond.✓ Correct
- (C)Graphite has higher thermal conductivity than diamond.
- (D)Graphite has higher C-C bond order than diamond.✓ Correct
Answer: (B), (D)
Solution
Diamond is harder than graphite due to its 3D tetrahedral network, so (A) is incorrect. Graphite has delocalized π-electrons making it a good electrical conductor, while diamond is an insulator, so (B) is correct. Diamond has higher thermal conductivity due to its rigid structure, so (C) is incorrect. In graphite, C-C bonds have partial double bond character (bond order ≈ 1.33), while in diamond all bonds are single (bond order = 1), so (D) is correct. The answer is (B), (D).
JEE Advanced · 2012 · 08 Apr 2012 · Paper 2 · One or more correct options