Answer
a) Cycloalkanes are cyclic hydrocarbons having C-C single bond and here C atoms are bonded together to form a ring.
(For example, the ring is trigonal when 3 Carbon is bonded together; square if 4 carbon atoms are bonded together etc.).
Simplest cycloalkane is Cyclopropane ($C_{3}H_{6}$)
b) General formula of Cycloalkanes : $C_{n}H_{2n}$
(N.B. Here, the minimum value of n is 3. )
c) Three example of cycloalkanes are given below with their structural formulas and names:
Work Step by Step
a) Cycloalkanes means cyclic saturated hydrocarbons. Cyclic means ring consists of Carbon atoms. Carbon atoms bonded together to form a ring. Saturated means all bonds are single bond ($\sigma bond$). Hydrocarbon means organic compounds having C and H atoms.
b) As cycloalkanes have the ring Carbon atoms so there is no terminal Carbon atoms. That's why their general formula will be $C_{n}H_{2n}$ which is different from general formulas of alkanes $C_{n}H_{2n+2}$
c) Naming Cycloalkanes is done by count the no. of ring Carbon first. No. of C =3 means 'prop'; No. of C = 4 means 'but' etc. These are word root. suffix or ending name is 'ane' for alkanes and cyclo is added before word root. If substituent present then the substituent name is added before 'cyclo'.
General formula for naming cycloalkanes: (substituent name)(cyclo)(word root)(ending name).
