Equilibrium - Topic 7

When the rates of forward and reverse reaction are equal in a closed system

The formula that determines the equilibrium constant for a reaction

K∨c

Its magnitude indicates the extent of a reaction at equilibrium and its temperature dependence

A substance that has no impact on the equilibrium position of a reaction or the equilibrium constant

The reaction quotient, Q, measures the relative amount of products and reactants at a point of time during a reaction

Q is the equilibrium constant’s expression with non-equilibrium concentrations

Temperature, concentration, and pressure

When in a reaction, both the forwards and reverse reactions are occurring simultaneously, with both products and reactants being constantly interconverted

Water cycle, condensation in hot pots, sealed bottles of carbonated beverages

When equilibrium has been reached such that interconversion no longer results in a net change of either products or reactants

⇌ rather than →

The solid will begin to dissolve, meaning that the rate of dissolution and precipitation are not equal, however once the solid has been dissolved as much as possible, the dissolution and precipitation rates become equal, resulting in a dynamic equilibrium

When sodium chloride is dissolved in water

The physical conditions, chemical conditions, and the existence of a catalyst

In a homogenous equilibrium, all substances are in the same state, and in a heterogenous equilibrium, substances are in differing states

Whether the reactants or products are favoured

That at a given temperature, the ratio of the concentration of products to the concentration of reactants is a constant

This represents that the constant is calculated using the concentration values of substances in the reaction

If Kc is big, the forwards reaction is favoured at the temperature and if Kc is small, the reverse reaction is favoured and the specific reaction is unfavourable at the given temperature

It is now 1/Kc

It is now √Kc

It is now Kc²

It is now Kc₁ + Kc₂ and so on

It makes it favour the forwards reaction

It makes it favour the reverse reaction

Water is a pure substance, therefore its concentration and volume will increase proportionally, making there no change in the concentration overall. Despite this, the reaction is still impacted because the concentration of any aqueous identities will be changed

The endothermic reaction would be favoured, which can then determine whether the forwards or reverse reaction would be favoured

The exothermic reaction would be favoured, which can then determine whether the forwards or reverse reaction would be favoured

A change in volume or pressure

Because the two are inversely proportional, as detailed by Boyle’s law

The reaction will favour the side with the lesser stoichiometric mole ratio

The reaction will favour the side with the greater stoichiometric mole ratio

If a change is made to a system that is in equilibrium, the balance between the forward and reverse reactions will shift to offset this change and return the system to equilibrium

Cause and effect is used to describe an event that is resulting from another previous event, which is often used to develop hypotheses (if, then, because). This could connect to Le Châlalier’s Principle as it details the result of a change on a system, however the concepts do not directly connect because the changes are not always set in stone

The Haber process is a synthesis of ammonia from its elements developed by Fritz Haber, a German chemist

The process helps produce fertilizers that are difficult to naturally find due to large populations and has single handedly ensured that agriculture is advanced enough to support the ever growing population

N₂(g) + 3H₂(g) ⇌ 2NH₃(g)

Fritz Haber was responsible for saving an incomprehensibly large amount of people due to his advances in agriculture, however he is also known for being the “father of chemical warfare”. During WWI, he worked with the German Army to create poisonous gases that could be used against their enemies. Therefore, he was responsible for both saving and killing many thousands of people. Were his advances good or bad? Do they cancel each other out?

The concentration of products is higher than at equilibrium. The reverse reaction will be favoured until equilibrium is reached

The concentration of reactants is higher than at equilibrium. The forwards reaction will be favoured until equilibrium is reached

I → Initial

C → Concentration

E → Equilibrium