If K_sp of Ag₂CO₃ is 8 $$ \times $$ 10^–12, the molar solubility of Ag₂CO₃ in 0.1 M AgNO₃ is -

8 g of NaOH is dissolved in 18g of H₂O. Mole fraction of NaOH in solution and molality (in mol kg^–1) of the solution respectively are -

The increasing order of the reactivity of the following with LiAlH₄ is

The upper stratosphere consisting of the ozone layer protects us from sun's radiation that falls in the wavelength region of -