Equilibrium reactions in industry Flashcards
Why is yield important in industrial reversible reactions?
The yield determines how much of a desired product is obtained, affecting efficiency and cost - effectiveness in industrial production
Why is yield not the nyl factor considered in industrial processes?
Other factors such as reaction rate, energy costs, safety concerns and equipment expense must be balanced to ensure ecimovic validity
What are some economic considerations in industrial reactions?
COsts of high temperatures, high pressures, specialised equipment and energy consumption must be considered when optimising conditions
What is the Haber process?
An industrial process used to produce ammonia from nitrogen and hydrogen using a reversible reaction
What is the chemical equation for the Haber process?
N₂ (g) + 3H₂ (g) ⇌ 2NH₃ (g) ΔH = -92 kJ mol⁻¹
What are the raw materials used in the Haber process?
Nitrogen (from the air) and hydrogen (from natural gas or electrolysis of water)
How do temperature and pressure affect ammonia yield?
Low temperature increases yield, since the reaction is exothermic, but slows the rate
High pressure increases the yield (since fewer gas molecules are produced) but is costly and dangerous
Why is compromise needed in the Haber process?
While low temperatures gives higher yield, it slows reaction rate. High pressure increases yield but is expensive and risky, so moderate conditions are used
What catalyst is used in the Haber process?
An iron catalyst is used to speed up the reaction without affecting the equilibrium position
Why is the iron catalyst used in pea - size lumps?
To increase surface area, allowing more gas molecules to react and improving reaction efficiency
Why do the reactant gases in the Haber process not reach full equilibrium?
The gases flow continuously over the catalyst, so they do not spend enough time in contact with it to reach full equilibrium
Why does the iron catalyst need to be replaced every five years?
It becomes poisoned by impurities in the gas stream, reducing its effectiveness
How is ammonia separated from the reaction mixture?
Then ammonia is cooled, turning it into a liquid, which is then piped off
How is ethanol made from ethene?
By hydration, which involves adding water to ethene
Why is the hydration of ethene a reversible reaction?
Some ethanol decomposes back into ethene and water under reaction conditions
