Govt Exams
Mole fraction = vapor pressure of water / total atmospheric pressure = 23.8 / 760 = 0.0313
Cu²⁺ + 2e⁻ → Cu. For deposition of 1 mole Cu, 2 moles of electrons are required. So 2 moles e⁻ deposits 1 mole Cu.
pH = -log[H⁺], so [H⁺] = 10⁻ᵖᴴ = 10⁻⁴ = 1 × 10⁻⁴ M.
In endothermic reactions, ΔH is positive because heat is absorbed from surroundings. The system absorbs energy.
For first-order reactions, t₁/₂ = 0.693/k = 0.693/0.693 = 1.0 s.
E°cell = E°cathode - E°anode = 0.80 - (-0.40) = 1.20 V. A positive E°cell indicates a spontaneous galvanic cell.
At constant T and P, the Gibbs free energy change (ΔG = ΔH - TΔS) determines spontaneity. If ΔG < 0, the reaction is spontaneous.
The given reaction forms 2 moles of H₂O with ΔH° = -572 kJ/mol. Therefore, for 1 mole of H₂O, ΔH° = -572/2 = -286 kJ/mol.
Moles of sucrose = 342/342 = 1 mol. Molarity = 1 mol/1 L = 1.0 M
For l = 2 (d-subshell), ml values range from -2 to +2, giving 5 orbitals