We must write structural formula of:
1. 4 Hydrogen
1 Carbon
2. 4 Hydrogen
2 Carbon
(involves double bond)
3. 6 Hydrogen
3 Carbon
(there is one-double bond between two C atoms)
4. 2 Hydrogen
2 Carbon
(involves triple bond)
5. 4 Hydrogen
3 Carbon
(there is one-triple bond between two C atoms)
