A Level H2 Chemistry 2021 Paper 3 Answers -

A Level H2 Chemistry 2021 Paper 3 Answers: A Comprehensive Guide

1. ICE table (Initial, Change, Equilibrium in moles).
2. Convert to equilibrium concentrations (divide by volume in dm³).
3. ( K_c = \frac[C]^c [D]^d[A]^a [B]^b ) – omit solids/pure liquids.
4. Include units if required.

• ( m ) is total mass of solution (usually assume 1 g cm⁻³ density for dilute aq).
• Specific heat capacity ( c ) = 4.18 J g⁻¹ K⁻¹ unless otherwise stated.
• Sign errors lose 1 mark.

Common mark scheme notes:

• Answer: The standard electrode potential is the potential difference (voltage) measured at standard conditions (1 atm, 1 M, 298 K) between a standard hydrogen electrode and an electrode under standard conditions.

What is the term for the process by which a molecule gains an electron? Answer: D (Reduction)