InterviewSolution
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Explain giving reasons why:(i) Ionic solids conduct electricity in the molten state, but not in solid-state.(ii) A solution of sodium chloride has no effect on litmus, but a solution of zinc |
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Answer» (i) In solid-state of a substance (ionic compound) ions are not free to move but in the molten (liquid) state they are free to move towards oppositely charged electrodes on passing an electric current. Hence, an ionic substance conducts electricity in the molten state and not in the solid-state. (ii) Sodium chloride does not undergo hydrolysis when dissolved in water, as it is salt of strong acid and a strong base and solution remain neutral. Zinc chloride is a salt of strong acid and weak base so it undergoes hydrolysis in water (cationic hydrolysis) forming less dissociated Zn(OH)2 (a weak base) and strong acid HCl which is almost completely dissociated. Therefore, the concentration of H+ ions increases and the solution becomes acidic and turns blue litmus red. |
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