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Surface Chemistry — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistrySurface Chemistry3 Marks
Question
Define the following terms with an example in each:
  1. Lyophobic colloids.
  2. Homogeneous catalysis.
  3. O/W emulsion.
✓

Answer

  1. The particles of the dispersed phase have no affinity for the dispersion medium/solvent repelling (hating) colloidal sols.
Example: metal and their sulphides
  1. The reactant and the catalyst are in the same phase.
$\text{CH}_3\text{COOCH}_3\text{(I)}+\text{H}_2\text{O(I)}\xrightarrow{ \text{ }\text{ }\text{HCL(I)}\text{ }\text{ }}\text{CH}_3\text{COOH(aq)}+\text{CH}_3\text{OH(aq)}$
  1. Oil is dispersed in water/Oil is dispersed phase and water is dispersion medium.
Ex- milk

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