Ammonia Flashcards
1
Q
Uses of ammonia
A
- Most important use is for making fertilizers
- Also used in making of plastics, explosives, refrigerants
2
Q
How is nitrogen obtained for the Haber process?
A
- Nitrogen is obtained from the fractional distillation of liquid air.
- Air is cooled and compressed into a liquid and seperated by fractional distillation to obtain nitrogen gas
3
Q
How is hydrogen obtained for the Haber process
A
- Hydrogen is obtained from the cracking of petroleum. Cracking is breaking down long hydrocarbon chains into smaller molecules
- Example from organic chem
C8H18 → C5H10 + C3H6 + H2
4
Q
Equation of reaction of nitrogen and hydrogen (Haber process)
A
N2(g) + 3H2(g) ⇌ 2NH3(g)
5
Q
Conditions for Haber process
A
- Pressure of 250 atm
- Temperature of 450°C
- Presence of finely divided iron catalyst
6
Q
Displacement of ammonia from its salts
A
Ammonia salts can react with alkalis with heating to produce ammonia gas
heat NH4Cl(s) + NaOH(aq) → NH3(g) + H2O(l) + NaCl(aq)
7
Q
Why are unreacted hydrogen gas and nitrogen gas recycled during the Haber process
A
This is done in order to save money as the reaction is reversible, and to obtain a higher yield of ammonia gas (recycled unreacted H2 and N2 is used so that do not need to produce more N2 and H2 for the reaction to occur)
