At a certain temperature the reaction N₂O₄(g) ⇌ 2 NO₂(g) K₍c₎ = 0.25 is established…
CHEMISTRY · Multi-part · A Level · Chemistry · Chemical equilibria (Le Chatelier’s principle and Kc) · Chemical equilibria (Le Chatelier’s principle and Kc)
Problem
At a certain temperature the reaction
N₂O₄(g) ⇌ 2 NO₂(g) K₍c₎ = 0.25
is established in a rigid container that will be represented by exactly 20 total gaseous particles in a particulate diagram. No other species are present.
Answer the following questions.
(a) Write the equilibrium‐constant expression for K₍c₎ for this reaction.
(b) Let x represent the number of N₂O₄ particles in the final diagram. Derive an algebraic relationship between x and the number of NO₂ particles using both the stoichiometry of the reaction and the given value of K₍c₎.
(c) Using the relationship from part (b) and the requirement of exactly 20 total particles, determine integer numbers of N₂O₄ and NO₂ particles that satisfy K₍c₎ = 0.25 as closely as possible. Show all work and clearly state your final chosen particle counts.
(d) Explain why your solution represents the smallest whole‐number particle set that fulfills both the total‐particle constraint and the equilibrium condition.
(e) Describe in complete sentences what your finished particulate diagram would show, referring specifically to relative particle numbers and any visual cues you would include to distinguish the two species.