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Flashcards in C2g Deck (14)
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1
Q

Where does the hydrogen and nitrogen for the haber process come from?

A
  • nitrogen from air

- hydrogen from cracking oil fractions and natural gas

2
Q

What are the conditions for the haber process?

A
  • 200 atmospheres
  • 450C
  • iron catalyst
3
Q

Why can’t the pressure be too high or low in the haber process?

A
  • high pressure increases the percentage yield of a reaction

- but requires expensive material to handle the pressure and is dangerous

4
Q

Why can’t the temperature be too high or too low in the haber process?

A
  • high temperature, speeds up reaction and decreases the percentage yield
  • low temperature slows reaction but increases yied
5
Q

Why is a catalyst used in the haber process?

A
  • to speed up the reaction
  • which gets it to equilibrium proportions faster (catalyst doesn’t affect the position of equilibrium)
  • without catalyst temperature would need raising
6
Q

What do production costs depend on?

A
  • price of energy
  • cost of raw materials
  • labour costs
  • plant costs (equipment)
  • rate of reduction
7
Q

What does optimum conditions mean?

A

-condition that give the lowest production cost per kg of product

8
Q

How does the price of energy affect the cost of production?

A
  • industries need to keep energy bills low

- if reaction needs high temperature, running cost will be higher

9
Q

How does the cost of raw materials affect the cost of production?

A

-keep this at a minimum by recycling un-reacted materials

10
Q

How does the labour costs affect the cost of production?

A
  • everyone working in the company needs payment
  • labour-intensive process(i.e require many people) can be expensive
  • automation cuts running costs by reducing the number of people involved
  • companies must always weigh savings on wage bills against initial cost and running cost of machinery
11
Q

How does the plant (equipment) cost affect the cost of production?

A
  • cost of equipment depends on conditions it has to cope with
  • equipment that can deal with very high pressures are more expensive than equipment needed to deal with atmospheric pressure
12
Q

How does the rate of production affect the cost of production?

A
  • the faster the rate of reaction the the less time and costs spent on production
  • rates of reactions often increased by catalysts
  • increase in production rate has to balance the cost of buying a catalyst and replacing any that get lost
13
Q

What is meant by compromised conditions?

A
  • optimum temperature that gives fast reaction rate and reasonable percentage yield
  • its a compromise
14
Q

What is the process of the haber process?

A

1-hydrogen and nitrogen enter at ratio of 3:1
2-heated at 450C, put under pressure at 200atm and catalysed by trays of iron in a reaction vessel
3-condenser at the bottom to condense the now ammonia into liquid
4-liquid ammonia is removed to stop reaction from reversing
4-the unused reactants stay as gases and are recycled