Chemistry notes

Yield and atom Economy

Percentage yield = amount of product produced divided by maximum amount of product possible X100

  • Atoms are never lost or gained in a chemical reaction.
  • Atom economy = measure of the starting materials that end up as useful products.


RFM % mass = mass of element (Ar) divided by relative formula mass (Mr) X100


A mole = measure of the number of particles contained in a substance.

Element ------> mass of one mole = relative atomic mass

Compound ------> mass of one mole = relative formula mass.

1 of 2

Haber Process

The Haber process = Nitrogen (N2) + Hydrogen (3H ) ------> Ammonia ( 2NH )

  • Reversible reaction occurs in a closed system ------> equilibrium achieved when reactions occur at the same rate in the same direction.

To speed up reaction :-

  • Fe (iron) catalyst.
  • (large surface area, more collisions, increase rate.)
  • pressure compresses gases, - particles closer together, - more collisions, more reaction.
  • 200 atmospheres
  • 450 degrees - increase temp., increase rate more (harder collisions)
  • Increase yield - the product has fewer particles than the reactants.

High yield is large amount of product compared to what you started with.

2 of 2


No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »