Which of the following observations is found in the Tollens' test for aldehydes?

Among the following compounds,which will react with acetone to give a product containing $> C = N -$?

Which one of the following is produced when acetone is saturated with $HCl$ gas?

Carbonyl compounds undergo nucleophilic addition because of

When liquid $A$ is treated with a freshly prepared ammoniacal silver nitrate solution,it gives a bright silver mirror. The liquid forms a white crystalline solid on treatment with sodium hydrogensulphite. Liquid $B$ also forms a white crystalline solid with sodium hydrogensulphite but it does not give a test with ammoniacal silver nitrate. Which of the two liquids is an aldehyde? Write the chemical equations of these reactions also.

Explain the solubility of aldehyde and ketone compounds.