CBSE Class 10 Science 2018 · Paper 31/1 · Question 8

(a) Most carbon compounds are formed by covalent bonds (sharing of electrons), so they do not dissociate into ions. With no charged particles to carry a current, most carbon compounds are poor conductors of electricity. (b) Name: cyclohexane, ${\text{C}}_6{\text{H}}_{12}$. Structure: six carbon atoms joined in a ring by single bonds, each carbon atom also bonded to two hydrogen atoms (see the figure). Number of single bonds: $6$ carbon-carbon + $12$ carbon-hydrogen $=18$. Any other cycloalkane is also correct with its own count, for example cyclopentane, ${\text{C}}_5{\text{H}}_{10}$, with $15$ single bonds.