In which of the following, the sol is not correctly matched with respect to its charge? I. $\mathrm{Al}_2…

In which of the following, the sol is not correctly matched with respect to its charge? I. $\mathrm{Al}_2 \mathrm{O}_3 \cdot \mathrm{x} \cdot \mathrm{H}_2 \mathrm{O}$ sol; + ve sol II. Starch sol; +ve sol III. $\mathrm{TiO}_2$ sol; -ve sol IV. Methylene blue sol; +ve sol The correct answer is
  1. I, IV
  2. I, III
  3. II, III
  4. II, IV

Solution

Starch sol is a negatively-charged sol while $\mathrm{TiO}_2$ is a positively-charged sol. Thus, II and III are not correctly matched.

Asked in: AP EAMCET 2023 (16 May Shift 2)

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