7. Equilibrium HL

1.For the reaction below H2(g) + I2(g)  2HI(g) at a certain temperature, the equilibrium concentrations are (in mol dm–3) [H2] = 0.30, [I2] = 0.30, [HI] = 3.0   What is the value of K?

2. The value of the equilibrium constant for the reaction 2HI(g)  H2(g) + I2(g)   is 0.25 at 440°C. What would the value of the equilibrium constant be for the following reaction at the same temperature? H2(g) + I2(g)  2HI(g)

3. Hydrogen and carbon dioxide react as shown in the equation below. H2(g) + CO2(g)  H2O(g) + CO(g) For this reaction the values of Kc with different temperatures are

Temperature / K	Kc
500	7.76×10–3
700	1.23×10–1
900	6.01×10–1

Which statement for the reaction is correct?

4. The expression for the equilibrium constant for a reaction is Kc = At a certain temperature the values of [A], [B] and [C] are all 0.2 mol dm–3. What happens to the value of Kc when all three values are doubled to 0.4 mol dm–3?

5. A 1.0 dm3 reaction vessel initially contains 6.0 mol of P and 6.0 mol of Q. At equilibrium 4.0 mol of R is present. What is the value of Kc for the following reaction? P(g) + Q(g)  R(g) + S(g)

6. For the reaction below: H2(g) + I2(g)  2HI(g) at a certain temperature, the equilibrium concentrations, in mol dm–3, are [H2(g)] = 0.30, [I2(g)] = 0.30, [HI(g)] = 3.0 What is the value of K?

7. A liquid and its vapour are at equilibrium inside a sealed container. Which change will alter the equilibrium vapour pressure of the liquid in the container?