7. Equilibrium Flashcards
Equilibrium
Needs to be a closed system. When the rate of forward reaction is equal to the rate of the backward reaction in a reversible reaction, equilibrium is achieved.
2 types of equilibrium
Physical and Chemical
Physical is only when the state changes
Chemical is when a new substance is formed
Chemical Equilibrium
Chemical occurs when the concentrations of reactants and products in a chemical reaction remain constant over time
Le-Chatlier’s Principle
If we change the factors affecting equilibrium then the reaction will shift in the direction where the effect is minimised.
Factors Affecting Equilibrium
Temperature
Pressure
Concentration
Catalyst
Temperature affecting equilibrium
If you increase the temperature of an already existing exothermic reaction it will become an endothermic reaction.
Pressure
If you increase the pressure, the number of particles per unit volume increases.
Increasing- Equilibrium will shift where number of gaseous particles are less.
Decreasing- Equilibrium will shift where number number of gases are more.
Concentration
If concentration of reactants/ if concentration of products is decreased, it will shit towards the forward direction.
Catalyst
If catalyst is added, it will impact forward and backward reaction in the same manner, equilibrium will be achieved faster.
What chemical process gives amoneia
Nitrogen+Hydrogen
N2 + 3H2 → 2NH3
2NH3 is amoneia
Haber Process
An industrial process for producing ammonia by reaction of nitrogen with hydrogen
Factors Affecting Haber Process
Temperature
Pressure
How does temperature affect Haber’s process
Since the reaction is an exothermic reaction, we would need a lower temperature (450 degrees) to favour the forward reaction. However, to have a high rate of reaction we need a high temperature.
450 degrees is a compromise, low yield for high rate of reaction.
How does pressure affect Haber’s process
We would need a high pressure as there are fewer molecules of product than there are reactants. We also need a high pressure for high rate of reaction
Pressure: 200atm
Reactivity of metals
Metals less reactive than hydrogen:
Copper (Cu)
Silver (Ag)
Gold (Au)
Pt (Platinum)
Reduction
Loss of Oxygen
Gain of Hydrogen
Gain of electrons
The substance (reactant) which reduces is the oxidizing agent/ oxidant
Oxidation
Gain of Oxygen
Loss of Hydrogen
Loss of electrons
The substance which oxidizes is the reducing agent/ reductant
More reactive metals loose electrons more ____?
More reactive metals loose electrons more easily
Eg.
Cu2+(aq) + Zn(s) –> Zn2+(aq)+ Cu(s)
Zn(s) –> Zn2+ + 2e- (oxidation half reaction)
Cu2+(aq) + 2e- –> Cu (reduction half reaction)
Spectator ions
An ion that exists in a chemical reaction but doesn’t participate in it and remains unchanged. Spectator ions are present in the same state on both sides of the reaction
Which all physical forms dissociate (breakdown)?
Only aqueous solutions will dissociate into there corresponding ions.
Gas, solid and liquid will not dissociate.
Electrorod
Cathode and Anode
Cathode attracts cations (+)
Anode attracts anions (-)
Is a rod of metal or graphite through which an electric current flows into or out of an electrolyte.
Electrolyte
Is the ionic compound (liquid basically) in a molten or aqueous solution that conducts electricity
Covalent compounds electrolysis
They cannot conduct electricity therefore cannot undergo electrolysis
Electrolysis
When an electric current is passed through a molten or aqueous solution the compound decomposes (breaks down).
