Chemistry The Haber Process Unit 2

Haber Process

Nitrogen is reacted with hydrogen gas to make ammonia.

Used to make Amonia NH3

It is a colourless gas.

Nitrogen is obtained from air via frational distillation due to all gases having different boiling points.

Hydrogen is NOT found in the air, it is obtained from methane and steam and is extremely explosive.

Balanced Equation

Nitrogen + Hydrogen (reversible reaction arrows) Ammonia

N2 (gas) + 3H2 (gas) (reversible reaction arrows) 2NH3 (gas) + heat

Reversible Reaction arrows show that the reaction occurs in BOTH DIRECTIONS at the SAME RATE.
An equilibrium needs an air tight container (closed system)

Because the reaction is reversible, special condititons are chosen.

 Low Temperature

• @ low temp the reaction is EXOTHERMIC (heat given out to surroundings)
• @ low temp the reaction displaces to the right hand side to overcome the change ie/ Makes heat.
• This increases yield. Yield = % product made, in this case Ammonia
• @ low temp the rate slows down (remember: increasing temperature makes the reaction go faster)
• So a compromise…