NEET Solved Paper 2017 Question 44

Question: Ionic mobility of which of the following alkali metal ions is lowest when aqueous solution of their salts are put under an electric field?

Options:

A) Li

B) Na

C) K

D) Rb

Show Answer

Answer:

Correct Answer: A

Solution:

  • $ L{i^{+}} $ being smallest, has maximum charge density
    $ \therefore $ $ L{i^{+}} $ is most heavily hydrated among all alkali metal ions. Effective size of $ L{i^{+}} $ in aq solution is therefore, largest.
    $ \therefore $ Moves slowest under electric field.