Compound $$\mathrm{P}$$ is neutral, $$\mathrm{Q}$$ gives effervescence with $$\mathrm{NaHCO}_{3}$$ while $$\mathrm{R}$$ reacts with Hinsbergs reagent to give solid soluble in $$\mathrm{NaOH}$$. Compound $$\mathrm{P}$$ is

Strong reducing and oxidizing agents among the following, respectively, are :

Match List I with List II

Choose the correct answer from the options given below:

Number of bromo derivatives obtained on treating ethane with excess of $$\mathrm{Br}_{2}$$ in diffused sunlight is ___________