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?

Question

Dr. Abubacker · Accepted Answer

[Solution from source] Down the group the cation gets larger, the lattice energy of the ionic hydride falls and the M–H interaction weakens, so the hydrides decompose more easily. Thermal stability decreases LiH > NaH > KH > RbH > CsH. The reverse order would follow increasing metallic character, not the stability of the hydride. Answer (1).

Q. 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?

Explanation

Reviewed by Dr. Abubacker

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