Benzene on reaction with acetyl chloride in the presence of anhydrous $AlCl_3$ gave the product $P$. The product $P$ on reaction with methyl magnesium bromide followed by treatment with water furnished the product $Q$. The molecular formula of $Q$ is

Which of the following will not give $D.N.P.$ test?

How will you convert butan$-2-$one to propanoic acid?

The best reagent to carry out the following conversion is:
$3$-hydroxyethylcyclopentane-$1$-carbaldehyde $\rightarrow$ $1$-ethyl-$3$-methylcyclopentane (with a hydroxy group on the ethyl side chain).
(Note: The image shows the reduction of an aldehyde group $-CHO$ to a methyl group $-CH_3$ while keeping the secondary alcohol $-CH(OH)CH_3$ intact.)

The product $(A)$ of the reaction is:

An organic compound $(A)$ with molecular formula $C_8H_8O$ forms an orange-red precipitate with $2,4-DNP$ reagent and gives a yellow precipitate on heating with iodine in the presence of sodium hydroxide. It neither reduces Tollens' or Fehlings' reagent,nor does it decolourise bromine water or Baeyer's reagent. On drastic oxidation with chromic acid,it gives a carboxylic acid $(B)$ having molecular formula $C_7H_6O_2$. Identify the compounds $(A)$ and $(B)$ and explain the reactions involved.