Obtain the IUPAC name of the following compound systematically.
`CH_(3)CHO`
(ii) `CH_(3)CH_(2)COCH_(3)`
(iii) `ClCH_(2)-CH_(2)-CH_(2)-CH_(3)`

Explanation

(i) `CH_(3)CHO`
Step 1 : The parent chain consists of 2 carbon atoms.
The root word is ..Eth...
Step 2 : All are single bonds between carbon atom of the chain. So the primary suffix is ..ane...
Step 3 : Since the compound contains the - CHO group, it is a aldehyde. The secondary suffix is ..al...
`therefore` The name of the compound is Eth + ane + al = Ethanal
(ii) `CH_(3)CH_(2)COCH_(3)`
Step 1 : The parent chain consists of 4 carbon atoms.
The root word is ..But...
Step 2 : All are single bonds between carbon atom of the chain. So the primary suffix is ..ane...
Step 3 : Since the compound contains the - CO - group, it is a ketone group. The secondary suffix is ..one...
`therefore` The name of the compound is But + ane + one = Butanone
(iii) `ClCH_(2)-CH_(2)-CH_(2)-CH_(3)`
Step 1 : The parent chain consists of 4 carbon atoms.
The root word is But...
Step 2 : All the single bonds between carbon atom of the chain. So the suffix is ..ane...
Step 3 : Since the compound contains the - Cl substituent. The prefix is Chloro.
Step 4 : The locant number of - Cl is 1 and thus prefix is 1 -Chloro.
`therefore` The name of the compound is 1 -Chloro + But - ane = 1 -Chlorobutane.