The energy required to break one mole of Cl–Cl bonds in Cl₂ is 242 kJ mol^–1. The longest wavelength of light capable of breaking a single Cl – Cl bond is
(c = 3 x 10⁸ ms^–1 and N_A = 6.02 x 10²³ mol^–1)

Ionisation energy of He⁺ is 19.6 x 10^–18 J atom^–1. The energy of the first stationary state (n = 1) of Li²⁺ is

The correct sequence which shows decreasing order of the ionic radii of the elements is

If 10^–4 dm³ of water is introduced into a 1.0 dm³ flask to 300 K, how many moles of water are in the vapour phase when equilibrium is established ?
(Given : Vapour pressure of H₂O at 300 K is 3170 Pa ; R = 8.314 J K^–1 mol^–1)