Class 11th

For a reaction,
4M(s) + nO₂(g) → 2M₂Oₙ(s),
the free energy change is plotted as a function of temperature. The temperature below which the oxide is stable could be inferred from the plot as the point at which

At 20.0 mL solution containing 0.2 g impure H2O2 reacts completely with 0.316 g of KMnO4 in acid solution. The purity of H2O2 (in %) is (mol. wt. of H2O2 = 34; mol. wt. of KMnO4 = 158 )

Consider the following equations :
2Fe²⁺ + H₂O₂ → xA + yB (in basic medium)
2MnO₄⁻ + 6H⁺ + 5H₂O₂ → x'C + y'D + z'E (in acidic medium)
The sum of the stoichiometric coefficients x, y, x', y' and z' for products A, B, C, D and E, respectively, is

Five moles of an ideal gas at 1 bar and 298 K is expanded into vacuum to double the volume. The work done is :

The shortest wavelength of H atom in the Lyman series is λ₁. The longest wavelength in the Balmer Series of H⁺ is:

The reaction in which hybridization of the underlined atom is affected is:

The molecule in which hybrid MOs involve only one d-orbital of the central atom is :

An alkaline earth metal ' M' readily forms water soluble sulphate and water insoluble hydroxide. Its oxide MO is very stable to heat and does not have rock-salt structure. M is:

The mass of ammonia in grams produced when 2.8 kg of dinitrogen quantitatively reacts with 1 kg of dihydrogen is

The elements with atomic numbers 101 and 104 belong to, respectively