Answer
See explanation
Work Step by Step
a) When propene reacts with $Br_{2}$, addition reaction happens where two Br atoms are added to the two double bonded C atoms and double bond breaks to single bond. We get the desired product.
b) To synthesize acetone, we can take 2-propanol as starting material which has 3 Carbon in it and $-CH(OH)-$ group is present. It can participate in oxidation reaction in presence dil. $H_{2}SO_{4}$ and $K_{2}Cr_{2}O_{7}$ and $-CH(OH)-$ group becomes $-CO-$. so, we get the desired product.
c) To synthesize tert-butyl alcohol, we have to take 2-methyl propene as a starting material which when reacts with $H_{2}O$ in presence of mineral acid, one H is added to the C1 carbon and one OH is added to C2 carbon & we get the desired product as major product.
d) To synthesize propanoic acid from an alcohol we have to select propanol as starting material which can oxidized to propanoic acid in presence of oxidizing agent like dil. $H_{2}SO_{4}$ and $K_{2}Cr_{2}O_{7}$ and we get the desired product.
