Which from following instruments is used to determine the crystal structure?

Solubility of $$\mathrm{AgCl}$$ is $$7.2 \times 10^{-7} \mathrm{~mol} ~\mathrm{dm}^{-3}$$. What is it's solubility product?

Identify compound $$\mathrm{A}$$ used in following reaction.

Benzoic acid $$\underset{\Delta}{\stackrel{A}{\longrightarrow}}$$ Benzoyl chloride + Phosphorous oxychloride + Hydrogen chloride

In a first order reaction concentration of reactant decreases from 20 m mol to 10 m mol in 1.151 min. What is rate constant?