If formaldehyde and potassium hydroxide are heated,then we get

Which one of the following gives a yellow precipitate with iodine and $NaOH$ solution?

$CH_3-CO-CH_3$ $\xrightarrow{NaCN/HCl} A$ $\xrightarrow{H_3O^{+}/\Delta} B$. In the above sequence of reactions,$A$ and $B$ are:

The appropriate reagent for the transformation shown below is:

Which one of the following on treatment with $50 \% \text{ aq. } NaOH$ yields the corresponding alcohol and salt of carboxylic acid?

The major product formed in the following reaction is: