For the gaseous reaction B₂(g) ⇌ 2 B(g) a sealed container is filled with 16 B₂…
CHEMISTRY · Multi-part · A Level · Chemistry · Chemical equilibria (Le Chatelier’s principle and Kc) · Chemical equilibria (Le Chatelier’s principle and Kc)
Problem
For the gaseous reaction
B₂(g) ⇌ 2 B(g)
a sealed container is filled with 16 B₂ molecules and no B atoms. After the system reaches equilibrium at a fixed temperature, the particulate diagram shows 4 B₂ molecules and 24 B atoms.
A student then prepares three new containers (P, Q, and R) at the same temperature and volume, with the following initial particle counts:
• P: 4 B₂ molecules, 24 B atoms
• Q: 10 B₂ molecules, 12 B atoms
• R: 1 B₂ molecule, 30 B atoms
Respond to the prompts below.
(a) Using only the initial and equilibrium particle counts given for the original container, determine the numerical value of the equilibrium constant K.
(b) For each of the new containers P, Q, and R, determine whether the system as prepared is at equilibrium. If it is not at equilibrium, state the direction (toward reactants or toward products) in which the reaction will proceed to reach equilibrium.
(c) Once each of the three new containers has reached equilibrium, rank them from smallest to largest extent of the forward reaction (least to greatest percentage conversion of B₂ to B). Provide particulate-level justification for your ordering.