Answer
a) 1,3-dichlorobutane
b) 1,1,1-trichlorobutane
c) 2,3-dichloro-2,4-dimethylhexane
d) 1,2-difluoroethane
Work Step by Step
a) Count the no. of C atoms in straight chain. Here, it is 4. Hence, root name is 'but'. Now, numbering the straight chain C atoms is done so that the substituents will get the minimum number. Now, if we numbering from left side, 'Cl' atoms get C1 and C3 position which are minimum positions. so, 1,3-dichloro is added before root name and ending name is 'ane' for alkane.
b) No. of C in straight chain = 4. hence, root name is 'but'. Now, three Cl atoms are present as substituents at C1 position if we numbering the C atoms of straight chain from right side. So, '1,1,1-trichloro' is added before root name and ending name is 'ane' for alkane.
c) No. of C in longest straight chain = 6. hence, root name is 'hex'. now, if we numbering from right terminal side then two methyl groups get C3 and C5 position and two Cl atoms get C4 and C5 positions. If we numbering from left side then two methyl gets C2 and C4 positions and two Cl atoms get C2 and C3 position. So, numbering should be done from left side. '2,3-dichloro-2,4-dimethyl' is added before root name and ending name is 'ane' for alkane.
d) No. of C in straight chain = 2. hence, root name is 'eth'. Numbering the C atoms in straight chain. Now, two fluorine atoms are present at C1 and C2 positions respectively, so, '1,2-difluoro' is added before root name and ending name is 'ane' for alkane.
