07: chemical equilibria

Question 1

dynamic equilibrium

Answer 1

a reversible reaction is in dynamic equilibrium when
1. rate of forward and backward reactions are equal
2. concentrations of reactants and products remain constant

Question 2

position of equilibrium (POE)

Answer 2

is the proportion of products to reactants in the equilibrium mixture

Question 3

reversible reactions

Answer 3

a reversible reaction is a reaction that proceeds in both the forwards and backward direction. the reaction mixture contains quantities of all reaction species in the system.

Question 4

Kc constant

Answer 4

for a reversible reaction aP + bQ ↔ cR + dS

there is a fixed relationship between the equilibrium concentrations of reactants and products and it can be expressed as

Kc = [products]^coefficients / [reactants]^ coefficients
where Kc is the equilibrium constant for the reaction in terms of concentration. the powers to which the reactants and products are raised corresponds to the respective stoichiometric coefficients in the equation of the reversible reaction

Question 5

Le Chatelier’s Principle

Answer 5

Le Chatelier’s principle states that when a stress is applied to a reversible system at equilibrium, the position of equilibrium will shift to minimize the stress

Question 6

Haber process conditions

Answer 6

temperature: 500C

pressure: 250 atm

catalyst: finely divided iron catalyst