1. If the shortest wavelength of hydrogen atom in Lyman series is x, then longest wavelength in Balmer series of He⁺ is
a) $\frac{9x}{5}$
b) $\frac{36x}{5}$
c) $\frac{x}{4}$
d) $\frac{5x}{9}$

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2. The gas liberated on heating a mixture of two salts with NaOH , give a reddish brown presipitate with an alkaline solution of K₂HgI₄. The aqueous solution of the mixture on treatment with BaCl₂ gives a white precipitate which is sparingly soluble in conc. HCl . On heating the mixture with K₂Cr₂O₇ and conc. H₂OSO₄, red vapours are proced. The aqueous solution of mixture gives a deep blue colouration with potassium ferricyanide solution. Then, identify the radicals in the given mixture.
a) $NH_{4}^{+}, Fe^{3+}, SO_{4}^{2-}, NO_{2}^{-}$
b) $CO_{3}^{2-}, Fe^{2+}, SO_{4}^{-}, Cl^{-}$
c) $NH_{4}^{+}, Fe^{2+} , SO_{4}^{2-}, Cl^{-}$
d) $NH_{4}^{+}, Ca^{2+}, SO^{2-}_{4}, Cl^{-}$

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