What is the value of frequency of radiation when transition occurs between two stationary states that differ in energy by $$\Delta \mathrm{E}$$ ?

What is molar concentration of weak monobasic acid if dissociation constant is 5 $$\times$$ 10$$^{-8}$$ and undergoes 0.5% dissociation?

A substance containing hydrogen and releasing H$$^+$$ in aqueous medium is acid. Identify theory suggesting this concept, from following.

What is the molar conductivity of $$0.05 \mathrm{M}$$ solution of sodium hydroxide, if it's conductivity is $$0.0118 \mathrm{~S} \mathrm{~cm}^{-1}$$ at $$298 \mathrm{~K}$$ ?