Flashcards in C2g Deck (14):
Where does the hydrogen and nitrogen for the haber process come from?
-nitrogen from air
-hydrogen from cracking oil fractions and natural gas
What are the conditions for the haber process?
Why can't the pressure be too high or low in the haber process?
-high pressure increases the percentage yield of a reaction
-but requires expensive material to handle the pressure and is dangerous
Why can't the temperature be too high or too low in the haber process?
-high temperature, speeds up reaction and decreases the percentage yield
-low temperature slows reaction but increases yied
Why is a catalyst used in the haber process?
-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
What do production costs depend on?
-price of energy
-cost of raw materials
-plant costs (equipment)
-rate of reduction
What does optimum conditions mean?
-condition that give the lowest production cost per kg of product
How does the price of energy affect the cost of production?
-industries need to keep energy bills low
-if reaction needs high temperature, running cost will be higher
How does the cost of raw materials affect the cost of production?
-keep this at a minimum by recycling un-reacted materials
How does the labour costs affect the cost of production?
-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
How does the plant (equipment) cost affect the cost of production?
-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
How does the rate of production affect the cost of production?
-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
What is meant by compromised conditions?
-optimum temperature that gives fast reaction rate and reasonable percentage yield
-its a compromise