For making a distinction between $2$-pentanone and $3$-pentanone, the reagent to be employed is

What is the product obtained in the reaction?
$CH_3-CH=CH-CH_2-CHO \xrightarrow[(ii) H_3O^{+}]{(i) LiAlH_4} \text{product}$

If formaldehyde and $KOH$ are heated,then we get

In the scheme given below,the total number of intra molecular aldol condensation products formed from '$Y$' is

$A$ compound contains an $\alpha$-hydrogen atom and forms a $\beta$-hydroxy aldehyde in the presence of a dilute alkali. When this product is heated with a dilute acid,it yields unsaturated crotonaldehyde. Identify the compound.

Methyl ketone can be oxidized using the haloform reaction. The oxidized product (carboxylate ion) has $:-$