Question

The alkali metals form salt-like hydrides by the direct synthesis at elevated temperature. The thermal stability of these hydrides decreases in which of the following orders?

• A. \( \text{CsH} > \text{RbH} > \text{KH} > \text{LiH} \)
• B. \( \text{KH} > \text{NaH} > \text{LiH} > \text{RbH} \)
• C. \( \text{NaH} > \text{LiH} > \text{RbH} > \text{CsH} \)
• D. \( \text{LiH} > \text{NaH} > \text{RbH} > \text{CsH} \)

Hint:

The thermal stability of hydrides decreases as the size of the alkali metal cation increases.

Answer 1

The Correct Option is A