Oxidation of propyne with $SeO_2$ gives ....

Choose the sequence of steps that describes the best synthesis of but$-1$-ene from ethanol.

Identify product $B$ in the following sequence of reactions.
$1,2-\text{Dibromoethane}$ $\xrightarrow[\text{alc. } KOH]{\Delta} A$ $\xrightarrow{NaNH_2} B$

Which of the following compounds on hydration (addition of $H_2O$) with $H_2SO_4/HgSO_4/H_2O$ gives an aldehyde as the major product?

Which of the following reactants exhibits acidic properties?

The products of the following reaction $CH_3-C \equiv C-CH_2-CH_3 \xrightarrow[(2)\ H_2O]{(1)\ O_3}$ are: