CHEMISTRY FORM 4: CHAPTER 9

TIPS:

SYNTHESIS OF AMMONIA

• Compress 1 volume of nitrogen and 3 volume of hydrogen to 200 atm.
• Pass the mixture of gases through iron powder catalyst heated to 450°C.
• The ammonia gas is cooled to liquefy it.

PURPOSE OF ALLOYING

• Improve appearance of metal
• Prevent corrosion of metal
• Increases hardness of metal

Common mistakes:

1. Which of the following is the ideal condition for the manufacture of ammonia in the 
2. Haber process?

3. 	Temperature (°C)	Pressure (atm)	Catalyst
   A.	45	1	Iron
   B.	450	200	Iron
   C.	450	200	Vanadium(V) oxide
   D.	1000	1	Vanadium(V) oxide

   
   
   Students’ Answer : C
   Correct Answer: B. The catalyst used in the manufacture of ammonia is iron.


4. Which of the following is true about synthetic polymers?
   1. Synthetic polymers are biodegradable
   2. The use of synthetic polymers causes bronchitis
   3. We should reduce, reuse and recycle synthetic polymers
   4. The burning of synthetic polymers should be encouraged
   Students’ Answer : A
   Correct answer: C. Synthetic polymers are non biodegradable.