Govt Exams
[H⁺] = [OH⁻] indicates a neutral solution. At 25°C, Kw = [H⁺][OH⁻] = 1 × 10⁻¹⁴, so pH = 7, pOH = 7 confirms neutrality.
In a galvanic cell, anode is where oxidation occurs (loss of electrons). The cathode is where reduction occurs (gain of electrons).
E°cell = E°cathode - E°anode = 0.34 - (-0.76) = 1.10 V. Cu is cathode (reduction), Zn is anode (oxidation).
The coordination number is the number of ligands attached to the central metal ion. Here, 4 NH₃ ligands are bonded to Cu²⁺, so coordination number = 4.
Overall order = sum of exponents in rate law = 2 + 1 = 3 (third-order reaction). Note: order is determined experimentally, not from stoichiometry.
pOH = -log(1.0 × 10⁻⁸) = 8, so pH = 14 - 8 = 6. Since pH < 7, the solution is acidic.
For spontaneous processes, ΔG must be negative (ΔG < 0) at constant T and P. This is the fundamental criterion for spontaneity.
The color of the reaction vessel is irrelevant to reaction rate. Temperature, pressure, and concentration are major factors affecting reaction kinetics.
pH = -log[H⁺] = -log(2.5 × 10⁻⁵) = 4.60
In a galvanic cell, anode is negative, cathode is positive. Oxidation occurs at anode. Electrons flow from anode to cathode.