Question

Structure of the following compounds and the functional group present in them
1)butnoic
2)bromopropanr
3) butyne

Answer 1

See the attached photo

Answer 2

1.CH3-CH2-CH2-COOH
this is the formula of butanoic acid n f.g is carboxylic acid .
The prefix used here is oic acid.
2. CH3-CH2-CH2-Br is bromapropane.
the f.g present in this is haloalkane.
3. CH3-CH2-C≡CH it is butyne 
here is no f.g but the tripple bond and prefix used in tripple bond is yne.