Ammonia is made from nitrogen and hydrogen.
a.[1]
The reaction between nitrogen and hydrogen is reversible. Explain what this means.
b.[1]
The graph shows the percentage yield of ammonia obtained at different temperatures and pressures.
Describe how the percentage yield of ammonia changes as the pressure increases at 450∘C450^\circ\text{C}450∘C.
c.[1]
Write down a temperature and pressure which produce a 50%50\%50% yield of ammonia.