Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can explain, using the shape of the K expression, why a very large K means the equilibrium mixture is mostly products. (Guide: “What the size of K tells you”; Practice Q1)
- I can explain why a very small K means the reaction barely proceeds, and why the product concentration is still not zero. (Guide: Worked example 2; Practice Q2)
- I can say what “essentially to completion” means and why it is different from “complete”. (Guide: Worked example 1; Practice Q5)
- I can explain why K tells me nothing about how fast equilibrium is reached, and what a catalyst does and does not change. (Guide: “K tells you where, not how fast”; Practice Q6)
Calculation
- I can read K from a particle diagram for a 1 : 1 reaction, and draw a diagram that matches a given K. (Guide: Figure 1; Practice Q3)
- I can use [A] + [B] = total with [B]/[A] = K to find the composition of an A ⇌ B mixture and the percentage converted. (Guide: Worked example 1; Practice Q4)
- I can find the trace concentration of a product (or reactant) when K is very small (or very large). (Guide: Worked example 2; Practice Q5)
- I can show that a given set of concentrations is an equilibrium mixture by substituting into the K expression. (Practice Q7)
Reasoning
- I can use the value of K, with a short calculation, to justify or reject a claim about an equilibrium mixture. (Practice Q5, Q7)
- I can explain why K values are only directly comparable as ratios when the expressions have the same shape, and why K must be quoted with a temperature. (Guide: “Comparing K values fairly”; Practice Q7)
All ticked? Move on to Topic 7.6, Properties of the Equilibrium Constant, or return to the course roadmap.