WBCS.LIVE practice question

Which of the following alkali metal ions exhibits the absolute highest hydration enthalpy in an aqueous solution?

Solve this multiple-choice question and check the correct answer with its explanation below.

Answer options

  1. Li+
  2. K+
  3. Rb+
  4. Na+

Correct answer and explanation

Correct answer: Li+

Explanation: āœ… Correct Answer: A) Li+ šŸ“š Explanation: Hydration enthalpy is the massive amount of energy released when a mole of gaseous ions completely dissolves in water. It is inversely proportional to the ionic radius. Because the Lithium ion (Li+) is the absolute smallest among the alkali metals, it has the highest charge density. Therefore, it strongly attracts water molecules, resulting in the highest hydration enthalpy.