The reversible reaction D(g) ⇌ E(g) is at equilibrium in four identical containers. Particle counts are:
W: 10 D and 10 E X: 5 D and 5 E Y: 15 D and 5 E Z: 4 D and 12 E
Identify the two containers that must have identical equilibrium constants for the reaction and state, in one sentence, the reasoning based on the particle counts.