Irreversible and reversible Reactions

Question 1

What is dynamic equilibrium

Answer 1

When the rate of the forward reaction is the same as the rate of the reverse reaction

Question 2

What are the three factors that affect the position of equilibrium

Answer 2

Temperature
Pressure
Concentration

Question 3

What happens to the equilibrium if you increase the concentration of the reactants and the rate

Answer 3

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

Question 4

What affect does a catalyst have on the position of equilibrium and the rate of reaching equilibrium

Answer 4

Has no change on equilibrium but increases the rate of reaching equilibrium

Question 5

What happens to the equilibrium if you decrease the concentration of the reactants and what affect it has on the rate of reaching equilibrium

Answer 5

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

Question 6

What affect does an increase in temperature have on the position of equilibrium and the rate of the equilibrium

Answer 6

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

Question 7

What affect does a decrease in temperature have on the position of equilibrium

Answer 7

The equilibrium will move towards the exothermic direction therefore it will reduce more heat as a consequence rate to reach equilibrium decreases

Question 8

What affect does a high pressure have on the position of equilibrium and on the rate of reaching equilibrium

Answer 8

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.

Question 9

What affect does a decrease in pressure have on the position of equilibrium and on the rate of reaching equilibrium

Answer 9

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

Question 10

Gives two things that happen in a dynamic equilibrium

Answer 10

1. the forward and backward reactions still happen,and at the same rate
2. the concentration of all reacting substances do not change

Question 11

Give 3 differences in making ammonia through lab preparation compared to industrial process

Answer 11

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

Question 12

What is formula of ammonia

Answer 12

NH3

Question 13

Number of moles=

Answer 13

Volume(dm3) / 24

Question 14

Volume of gas=

Answer 14

Moles of gas x 24

Question 15

What does Avogadro law state

Answer 15

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

Question 16

Moles

Answer 16

Mass/ Mr

Question 17

Mass

Answer 17

Moles x Mr

Question 18

List 3 uses of ammonia

Answer 18

85% making fertilisers

5% explosives

5% textiles

Question 19

What is the equation for the haber process

Answer 19

N2 + 3H22NH3

Question 20

What are the raw materials of the haber process

Answer 20

Hydrogen-natural gas(methane reacting with steam)

Nitrogen-78% from the air

Question 21

Give the three reaction conditions for the haber process?

Answer 21

Temperature-lower(400-450C) compromise
Pressure-higher(200atm)compromise
Catalyst-iron to speed up reacting equilibrium

Question 22

Explain how a catalyst reduces costs

Answer 22

Catalysts reduce costs because they never run out and can be reused

Question 23

Give 3 cost factors that influence cost in Haber Process?

Answer 23

Energy
Staffing
Equipment

Question 24

How do you reduce labour costs in Haber process?

Answer 24

Get machinery and chemical plants that run 24/7 therefore not many people needed

Question 25

Ammonium sulfate

Answer 25

Ammonia + sulfuric acid ——>ammonium sulfate

Question 26

Ammonium phosphate

Answer 26

Ammonia + phosphoric acid ——>ammonium phosphate

Question 27

Potassium nitrate

Answer 27

Potassium hydroxide + nitric acid ——>potassium nitrate + water

Question 28

Give 2 reasons why they don’t carry out titration in industry in order to make fertilisers

Answer 28

1. The industry have to make fertilizers is a continuous process therefore making titration would not be suited as it is a batch process.
2. The industry is making the fertilizers on a bigger scale,titration only works in small scales

Question 29

State Le Chatelier’s Principle

Answer 29

If a change is imposed on an equilibrium the position of equilibrium will shift to minimize that change

Question 30

What does a catalyst do to the forward and backward reaction

Answer 30

Increases the rate of forward and backward reaction by the same amount but has no effect on position of equilibrium

Question 31

Explain why the Haber process does not use very high pressures or low temperatures

Answer 31

Because high pressure is to expensive to maintain

Because low temperatures reduces reaction rate

Question 32

Explain why the temperature chosen 450c is a compromise?

Answer 32

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.

Question 33

Explain why the pressure 200 atmposheres is a compromise

Answer 33

As the pressure increases,the equilibrium yielded ammonia and rate of reaction increases.However very high pressures need stronger and more expensive equipment.

Question 34

Atom economy=

Answer 34

Mr of desired product/Mr of all products X1000

Question 35

Percentage yield=

Answer 35

Actual yield/theoretical yield X100

Question 36

Why do you not get 100 percent yield?

Answer 36

Incomplete reactions

Practical loss from not transferring all content between containers

Question 37

Concentration(mol/dm^3)=

Answer 37

Moles/volume(dm^3)

Question 38

Moles=

Answer 38

ConcentrationXvolume

Question 39

Volume=

Answer 39

Moles/concentration