What is the wave number of lowest transition associated with Lyman series?

Vapour pressure of a pure solvent is 550 mm of Hg . By addition of a non volatile solute it decreases to 510 mm of Hg . Calculate the mole fraction of solute in solution.

Identify the product obtained when excess of benzoyl chloride is treated with dimethyl cadmium.

Rate constant of a reaction, $$ 2 \mathrm{NO}_2 \mathrm{Cl}_{2(\mathrm{~g})} \longrightarrow 2 \mathrm{NO}_{2(\mathrm{~g})}+\mathrm{Cl}_{2(\mathrm{~g})}$$

is 4.7672 minute $^{-1}$. Calculate half life of reaction.