Chemistry - Equilibrium

Equilibrium

the rate of forward reaction is equal to the rate of reverse reaction

Dynamic

the type of process that equilibrium is

Le Chatelier’s Principle

when a system in equilibrium is subjected to a stress, the system moves to oppose the stress

Catalyst

has no effect on the position of equilibrium

Haber Process

N₂+3H₂ ⇌ 2NH₃

Iron

catalyst used during the Haber process for the production of Ammonia

Increasing Temperature

equilibrium shifts to endothermic side

Decreasing Temperature

equilibrium shifts to exothermic side

Increasing Pressure

equilibrium shifts to the side with less moles

Decreasing Pressure

equilibrium shifts to the side with the more moles

Increasing Concentration

equilibrium shifts to the side that will use up the excess

Decreasing Concentration

equilibrium shifts to the side that will replace the chemical

Iron (iii) Chloride

mixed with potassium thiocyanate when investigating LC principle

Potassium Thiocyanate

mixed with iron (ii) chloride when investigating LC principle

Red

colour of iron thiocyanate complex

Dilute HCl

makes the solution yellow when added while investigate LC principle

Red

colour when solution is heated while investigating LC principle

Yellow

colour when solution is cooled while investigating LC principle

Contact Process

2 SO_2(g) + O_2(g) ⇌ 2 SO_3(g)

SO3

dissolves in water to form sulphuric acid

Vanadium Pentoxide

V2O5

catalyst used in the contact process

450 C

temperature in contact process

• a low temperature would give an unacceptable rate, too low, compromise between yield and rate

1 Atmosphere

pressure in contact process

• the increase in yield is not worth the extra cost

Kc>1

equilibrium lies towards the right

Kc<1

equilibrium lies towards the left

Kc=1

equilibrium lies in the middle

Temperature

only this has an effect on the value of Kc