Paraldehyde is a trimer of which of the following?

$A$ compound gives a positive test with $I_2/NaOH$ and is extracted from benzene by saturated $NaHSO_3$. It may be

Which statement is incorrect for the given reaction sequence: $CH_3-CN$ $\xrightarrow[(2) H_2O]{(1) CH_3MgBr} X$ $\xrightarrow{2,4-DNP} Y$?

Which of the following compounds does not give Tollen's test?

Which one among the following compounds will most readily be dehydrated under acidic condition?

Which of the following compounds has the most acidic hydrogen?