Answer:

1) CH3(CH2)6CH3

• why?

1. A straight chain alkane composed of 8 carbon atoms. Octane is a hydrocarbon and an alkane with the chemical formula C8H18, and the condensed structural formula CH3(CH2)6CH3.

2) CH2(CH2)3CH3

• why?

1. The molecular formula of pentane, or n-pentane, is C5H12 . The structural formula will be CH3CH2CH2CH2CH3 . The condensed structural formula will be CH2(CH2)3CH3

3) C6H10

4) CH3CCH

5) HC≡CH

• why?

1. The condenses structure formula of ethyne is HC≡CH. The Molecular formula of ethyne is – C2H2. That means ethyne contains 2 number of carbon atoms and 2 number of hydrogen atoms and the two carbon atoms are bonded with triple bonds.