STUDENT SPACE · TOPIC 6

Industrial equilibrium

Explain the compromises used in the Haber and Contact processes.

The essentials

N₂(g) + 3H₂(g) ⇌ 2NH₃(g). Nitrogen comes from air; hydrogen is commonly obtained from methane.
450 °C gives an acceptable rate with a useful equilibrium yield. High pressure favours ammonia and increases collision frequency.
2SO₂(g) + O₂(g) ⇌ 2SO₃(g). SO₂ comes from burning sulfur or roasting sulfide ores; oxygen comes from air.

Try each question before opening its hint or answer. Use paper for calculations and diagrams.

Where do nitrogen and hydrogen for the Haber process come from?

Need a hint for Question 1?

Compare one condition at a time and separate its effects on rate, yield and cost.

Check Question 1

Nitrogen from air; hydrogen commonly from methane.

State the pressure and catalyst for the Contact process.

Need a hint for Question 2?

Distinguish the Contact catalyst from the Haber catalyst.

Check Question 2

200 kPa (2 atm); vanadium(V) oxide, V₂O₅.

Explain why a factory does not use an arbitrarily high pressure for ammonia production.

Need a hint for Question 3?

Balance improved yield against equipment and running costs.

Check Question 3

Higher pressure costs more to generate, needs stronger equipment and creates greater safety demands.

Use Lesson 6 in your worksheet for written practice. Your teacher will discuss those answers in class.