Heat treatment of muscular pain involves radiation of wavelength of about 900 nm. Which spectral line of H atom is suitable for this purpose?

[R_H = 1 $$ \times $$ 10⁵ cm^–1, h = 6.6 $$ \times $$ 10^–34 Js, c = 3 $$ \times $$ 10⁸ ms^–1]

An organic compound is estimated through Duma's method and was found to evolve 6 moles of CO₂. 4 moles of H₂O and 1 mole of nitrogen gas. The formula of the compound is :

The correct match between items I and II is :

Item-I (Mixture)		Item-II (Seperation method)
(A)	H2O : Sugar	(P)	Sublimation
(B)	H2O : Aniline	(Q)	Recrystallization
(C)	H2O : Toluene	(R)	Steam distillation
		(S)	Differential extraction

The freezing point of a diluted milk sample is found to be –0.2^oC, while it should have been –0.5^oC for pure milk. How much water has been added to pure milk to make the diluted sample?