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Surface Chemistry — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistrySurface Chemistry3 Marks
Question
Give four examples of heterogeneous catalysis.
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Answer

  1. Oxidation of sulphur dioxide to form sulphur trioxide. In this reaction, Pt acts as a catalyst
$2\text{SO}_{2(\text{g})}\xrightarrow{\ \ \ \ \ \ \ \ \ \ \text{Pt}_{(\text{s})}\ \ \ \ \ \ \ \ }2\text{SO}_{3(\text{g})}$
  1. Formation of ammonia by the combination of dinitrogen and dihydrogen in the presence of finely divided iron.
$\text{N}_{2(\text{g})}+3\text{H}_{2(\text{g})}\xrightarrow{\ \ \ \ \ \ \ \ \ \ \text{Fe}_{(\text{s})}\ \ \ \ \ \ \ \ }2\text{NH}_{3(\text{g})}$

This process is called the Haber's process.
  1. Oswald's process: Oxidation of ammonia to nitric oxide in the presence of platinum.
$4\text{NH}_{3(\text{g})}+5\text{O}_{2(\text{g})}\xrightarrow{\ \ \ \ \ \ \ \ \ \ \text{Pt}_{(\text{s})}\ \ \ \ \ \ \ \ }4\text{NO}_{(\text{g})}+6\text{H}_2\text{O}_{(\text{g})}$
  1. Hydrogenation of vegetable oils in the presence of Ni.
$\text{Vegetable }\text{oil}_{(1)}+\text{H}_{2(\text{g})}\xrightarrow{\ \ \ \ \ \ \ \ \ \ \text{Ni}_{(\text{s})}\ \ \ \ \ \ \ \ }\text{Vegetable }\text{ghee}_{(\text{s})}$

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