What type of compounds is obtained in the first step of the Wolff-Kishner reduction of carbonyl compounds?

Which of the following reagents can form a hydrazone with alkanone?

$3$-hydroxybutanal is formed when $(X)$ reacts with $(Y)$ in dilute $(Z)$ solution. What are $X, Y$ and $Z$?

Aromatic aldehydes undergo disproportionation in the presence of concentrated sodium or potassium hydroxide to give the corresponding alcohol and acid salt. This reaction is known as:

Write the structural formulas and names of the four possible aldol condensation products from propanal and butanal. In each case,indicate which aldehyde acts as the nucleophile and which acts as the electrophile.

Choose the reactant whose aldol reaction would give jasmone.