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Sodium metal is dissolved in liquid ammonia (no copper present). Which of the following statements about the resulting solution is correct?
- (A) Na metal cannot be recovered from this solution by evaporation.
- (B) The liquid ammonia solution becomes a good conductor of electricity.
- (C) The liquid ammonia solution becomes paramagnetic.
- (D) A blue-coloured solution is obtained.
Correct answer: (D) A blue-coloured solution is obtained.
Solution
Na in liquid NH3 gives Na^+(am) + e^-(am). The solvated electron imparts a deep blue colour (D), makes the solution paramagnetic (C), and highly conducting (B). Na can be recovered on evaporation (A is false). The most basic and unambiguous correct statement is D.
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