The product formed by the reaction of chlorine with benzaldehyde in the absence of a catalyst is

Which of the following compounds gives the iodoform test?

Total number of nucleophiles from the following is $:-$ $NH_3, PhSH, (H_3C)_2S, H_2C=CH_2, \stackrel{\ominus}{O}H, H_3O^{\oplus}, (CH_3)_2CO, CH_3CH=NCH_3$

Which among the following compounds is a hemiacetal?

Acetaldehyde reacts with $C_2H_5MgCl$. The final product is

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