9: Making ammonia Flashcards
How does the cost of starting materials affect cost?
Different starting materials cost different amounts. The costs can be reduced if unreacted materials are recycled.
How does the cost of equipment needed affect cost?
Complex machinery and high pressures increase the cost of the plant
How does labour costs and wages affect cost?
The more workers who are needed, the higher the costs. The costs may be reduced if a process is automated.
How does the price of the energy needed affect cost?
Gas and electricity are expensive. The use of high temperatures increases the energy cost.
How does the speed at which the substance is made affect cost?
Catalysts increase the rate of chemical reactions, reducing costs.
What is ammonia used for?
Making fertilisers 80%
Making Nylon 7%
Making nitric acid 5%
Making other chemicals 8%
What is ammonia?
a gas with a sharp smell
What are fertilisers?
substances applied to the soil to replace the minerals in the soil in which the plants use up as they grow
What happens without fertilisers?
crop yields would be much smaller
What process is used for making ammonia?
The Haber Process
Equation for the Haber process
nitrogen + hydrogen = ammonia
N2 + 3H2 = 2NH3
Where does the hydrogen come from?
from cracking oil fractions or from natural gas
Where does the nitrogen come from?
the air
What are the conditions needed for the Haber Process?
high pressure
temperature around 450 degrees
iron catalyst
How are costs reduced in the Haber process?
by recycling unreacted hydrogen and nitrogen
