Question

Give four examples of heterogeneous catalysis ?

Answer 1

1. Oxidation of sulphur dioxide into sulphur trioxide in the presence of Pt.

$2S{O}_2\left(g\right)\stackrel{P{t}^{\left(s\right)}}{\to }2S{O}_3\left(g\right)$

The reactant is in gaseous state and catalyst is in the solid state.

2. Haber's process involves the combination of dihydrogen and dinitrogen to form ammonia. The reactants are gases while the catalyst iron is in solid state.

$N_2\left(g\right)+3H_2\left(g\right)\stackrel{F{e}^s}{\to }2N{H}_3\left(g\right)$

3. Oxidation of ammonia to form nitric oxide in the presence of platinum gauze in Ostwald's process.

$4N{H}_3\left(g\right)+5O_2\left(g\right)\stackrel{P{t}^{\left(s\right)}}{\to }4NO\left(g\right)+6H_{2}O\left(g\right)$

The reactants are in gaseous state while the catalyst is in the solid state.

4. Hydrogenation of vegetable oils to form saturated fats in the presence of nickel (solid) catalyst.

Vegetable oils $\left(l\right)+H_2\left(g\right)\stackrel{Ni\left(s\right)}{\to }$ Vegetable ghee (s)

One of the reactants is liquid (oil) and hydrogen is gas whereas the catalyst nickel is solid.