Which one is an example of heterogeneous catalysis?
- Hydrolysis of sugar catalysed by H+ ions.
- Decomposition of ozone in presence of nitrogen monoxide.
- Combination between dinitrogen and dihydrogen to form ammonia in the presence of finely divided iron.
- Oxidation of sulphur dioxide into sulphur trioxide in the presence of oxides of nitrogen.
Answer
(3) Combination between dinitrogen and dihydrogen to form ammonia in the presence of finely divided iron.
Solution
In heterogeneous catalysis the catalyst is in a different phase from the reactants.
(1) H+ ions and sugar are both in solution: homogeneous.
(2) O3 and NO are both gases: homogeneous.
(3) Haber process: N2(g)+3H2(g) Fe(s) 2NH3(g); gaseous reactants, solid catalyst: heterogeneous.
(4) Lead chamber process: SO2, O2 and NO are all gases: homogeneous.
Answer: (3)