CBSE Class 10 Answered

i.  4-Bromopent-2-ene. The C=C gets lower numeral than those substituents which are prefixed while naming them. Only COOH(R), C=O, OH precede a C=C or a CC tripple bond in that order. ii.  2,4-Dimethylpent-1-en-3-ol. Counting from eithe rside awards 3-position to OH, so give 2nd preference to C=C and 1st number to it.  The geometry about C=C is trans and E.   iii. It is a 7- carbon oic acid with 2-en and 4-hydroxy plus 5,5-dimethyl, having E (trans in this case) geometry about the C=C. Name it as (E)-4-Hydroxy-5,5-dimethylhept-2-enoic acid