Which of the following cations of alkali metals has least heat of hydration?
Correct answer: D. Cs+
- A. Li+
- B. Na+
- C. K+
- D. Cs+
Explanation
When considering the heat of hydration, the size and charge density of cations play a crucial role. In this case, Cesium ion (Cs+) stands out as it is the largest among alkali metal ions with the lowest charge density. This weak attraction to water molecules leads to the least heat of hydration. Therefore, option D is correct.Options A, B, and C are incorrect as they each have smaller sizes or higher charge densities compared to Cesium ion, resulting in higher heat of hydration values.
Last updated
About Reactions of Group I Elements
Group I elements have one valence electron, so their reactivity increases down the group as ionisation energy decreases. Their reactions with water, oxygen, hydrogen and halogens produce hydroxides, oxides, hydrides and halides, while the behaviour of lithium differs from the heavier metals because of its small ionic size.
Practise s-Block and p-Block Elements
1,359 free s-Block and p-Block Elements MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Chemistry questions like this
Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A elements are named as alkali metals because_______________?
A metal form strong base salts and stable carbonates. The metal is:
Alkali and alkaline earth metals impart colours when heated over the burner, it is due to?
Ammonia may be prepared by heating ammonium chloride with_______________?
Ammonia may be prepared by heating ammonium chloride with: