Draw and name the structural isomers which have the molecula

Draw and name the structural isomers which have the molecular formula C₄H₉Br.

Solution

CH2Br-CH2-CH2CH3 1-Bromo-nbutane CH3-CH2-CH2-CH2Br These two are the same compound
CH3-CHBr-CH2-CH3 2-Bromo-nbutane CH3-CH2-CHBr-CH3 These two are the same compound
CH2Br-CH=(CH3)2 1-Bromo-3-methyl-propane
CH3-CBr=(CH3)2 1-methyl-2-bromo-propane
CH3-CBr(CH3)-CH3 2-bromo-2-methylpropane

Hint - draw out as many straight line and branched formulae as you can. Then try different positions for the atom/group(in this case - Br). You choose the position to give as many isomers as you can with the lowest number