Which of the following reagents is used in the reaction shown below?

Benzoyl chloride $$\stackrel{?}{\longrightarrow}$$ Benzaldehyde

What is vapour pressure of a solution when $$2 \mathrm{~mol}$$ of a non-volatile solute are dissolved in $$20 \mathrm{~mol}$$ of water? $$\left(\mathrm{P}_1^0=32 \mathrm{~mm} \mathrm{Hg}\right)$$

Which among following amines has lowest $$\mathrm{pK}_{\mathrm{b}}$$ values?

Which of following elements forms crosslinks in vulcanization of SBR rubber?