Irreversible and reversible Reactions Flashcards
What is dynamic equilibrium
When the rate of the forward reaction is the same as the rate of the reverse reaction
What are the three factors that affect the position of equilibrium
Temperature
Pressure
Concentration
What happens to the equilibrium if you increase the concentration of the reactants and the rate
The equilibrium will move in the direction of the fewest moles of gas therefore making making more product and as a consequence there will be an increase on the rate of reaching equilibrium
What affect does a catalyst have on the position of equilibrium and the rate of reaching equilibrium
Has no change on equilibrium but increases the rate of reaching equilibrium
What happens to the equilibrium if you decrease the concentration of the reactants and what affect it has on the rate of reaching equilibrium
The equilibrium will move to the left to use up the product therefore making more reactant and as a consequence rate on reaching equilibrium decreases
What affect does an increase in temperature have on the position of equilibrium and the rate of the equilibrium
The equilibrium will move towards the endothermic direction because it will produce more heat as a consequence the rate of reaching equilibrium increases and the yield decreases
What affect does a decrease in temperature have on the position of equilibrium
The equilibrium will move towards the exothermic direction therefore it will reduce more heat as a consequence rate to reach equilibrium decreases
What affect does a high pressure have on the position of equilibrium and on the rate of reaching equilibrium
Equilibrium will move towards the side of the balanced equation of the fewest molecules of reacting gas and as a consequence rate of reaching equilibrium increases.
What affect does a decrease in pressure have on the position of equilibrium and on the rate of reaching equilibrium
Equilibrium will move towards the side of the balanced equation of the more molecules of reacting gas as a consequence the rate of reaching equilibrium decreases
Gives two things that happen in a dynamic equilibrium
- the forward and backward reactions still happen,and at the same rate
- the concentration of all reacting substances do not change
Give 3 differences in making ammonia through lab preparation compared to industrial process
Lab
Small scale
Buy the raw materials to make ammonia therefore fewer steps
Batch process
Industry
Large scale for huge population
Raw materials are made in industry therefore more steps needed
Continuous process
What is formula of ammonia
NH3
Number of moles=
Volume(dm3) / 24
Volume of gas=
Moles of gas x 24
What does Avogadro law state
States that equal volume of all gases,at the same temperature and pressure contain the same number of particles.
State that volume of one mole of any gas is 24dm3 at room temperature and atmosphere pressure
Moles
Mass/ Mr
Mass
Moles x Mr
List 3 uses of ammonia
85% making fertilisers
5% explosives
5% textiles
What is the equation for the haber process
N2 + 3H22NH3
What are the raw materials of the haber process
Hydrogen-natural gas(methane reacting with steam)
Nitrogen-78% from the air
Give the three reaction conditions for the haber process?
Temperature-lower(400-450C) compromise
Pressure-higher(200atm)compromise
Catalyst-iron to speed up reacting equilibrium
Explain how a catalyst reduces costs
Catalysts reduce costs because they never run out and can be reused
Give 3 cost factors that influence cost in Haber Process?
Energy
Staffing
Equipment
How do you reduce labour costs in Haber process?
Get machinery and chemical plants that run 24/7 therefore not many people needed
Ammonium sulfate
Ammonia + sulfuric acid ——>ammonium sulfate
Ammonium phosphate
Ammonia + phosphoric acid ——>ammonium phosphate
Potassium nitrate
Potassium hydroxide + nitric acid ——>potassium nitrate + water
Give 2 reasons why they don’t carry out titration in industry in order to make fertilisers
- The industry have to make fertilizers is a continuous process therefore making titration would not be suited as it is a batch process.
- The industry is making the fertilizers on a bigger scale,titration only works in small scales
State Le Chatelier’s Principle
If a change is imposed on an equilibrium the position of equilibrium will shift to minimize that change
What does a catalyst do to the forward and backward reaction
Increases the rate of forward and backward reaction by the same amount but has no effect on position of equilibrium
Explain why the Haber process does not use very high pressures or low temperatures
Because high pressure is to expensive to maintain
Because low temperatures reduces reaction rate
Explain why the temperature chosen 450c is a compromise?
As the temperature increases the equilibrium yield of ammonia decreases,but the rate of reaction increases.450c is low enough to obtain an acceptable yield of ammonia,but high enough to obtain it in an acceptable yield.
Explain why the pressure 200 atmposheres is a compromise
As the pressure increases,the equilibrium yielded ammonia and rate of reaction increases.However very high pressures need stronger and more expensive equipment.
Atom economy=
Mr of desired product/Mr of all products X1000
Percentage yield=
Actual yield/theoretical yield X100
Why do you not get 100 percent yield?
Incomplete reactions
Practical loss from not transferring all content between containers
Concentration(mol/dm^3)=
Moles/volume(dm^3)
Moles=
ConcentrationXvolume
Volume=
Moles/concentration
