Benzaldehyde and acetone can be best distinguished using

Fehling's solution is a mixture of two solutions. One of them is $CuSO_4$. What does the other solution contain?

The major product $(Y)$ in the following reactions is
$CH_3-CH(CH_3)-C\equiv CH$ $\xrightarrow[H_2O]{HgSO_4, H_2SO_4} X$ $\xrightarrow[(ii) \ conc. H_2SO_4 / \Delta]{(i) \ C_2H_5MgBr, H_2O} Y$

The final product $(C)$ in the given reaction sequence is
$C_6H_5COOH$ $\xrightarrow{SOCl_2} (A)$ $\xrightarrow[\text{anhy. } AlCl_3]{C_6H_6} (B)$ $\xrightarrow[\text{(ii) } KOH / (CH_2OH)_2]{\text{(i) } NH_2-NH_2} (C)$

Which of the following does not give a yellow precipitate with $NaOH + I_2$?

Write the reduction reaction of aldehydes and ketones.