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Chemistry · PYQ NEET UG 2022
हिन्दीGiven below are two statements: Statement I: In the coagulation of a negative sol, the flocculating power of the three given ions is in the order – \( \text{Al}^{3+} > \text{Ba}^{2+} > \text{Na}^+ \) Statement II: In the coagulation of a positive sol, the flocculating power of the three given salts is in the order – \( \text{NaCl} > \text{Na}_2\text{SO}_4 > \text{Na}_3\text{PO}_4 \) In the light of the above statements, choose the most appropriate answer from the options given below:
Correct answer · Option 1
Statement I is correct but Statement II is incorrect.
Explanation
According to Hardy-Schulze rule, flocculating power increases with the valency of the coagulating ion. For a negative sol, cation efficiency is \( \text{Al}^{3+} > \text{Ba}^{2+} > \text{Na}^+ \) (Statement I is correct). For a positive sol, anion efficiency is \( \text{PO}_4^{3-} > \text{SO}_4^{2-} > \text{Cl}^- \), meaning the flocculating power of salts is \( \text{Na}_3\text{PO}_4 > \text{Na}_2\text{SO}_4 > \text{NaCl} \). Thus Statement II is incorrect.
