The process \(\frac{1}{2}\)H2(g) + e– → H– (g) is endothermic (AH = +151 kJmol-1), yet salt like hydrides are known. How do you account for this?

The process \(\frac{1}{2}\)H2(g) + e– → H– (g) is endothermic (A

1.	The process \(\frac{1}{2}\)H2(g) + e– → H– (g) is endothermic (AH = +151 kJmol-1), yet salt like hydrides are known. How do you account for this?
Answer» It is true that formation of hydride(H^–) ion is an endothermic process, yet alkali and alkaline earth metals from salt like hydrides. This is due to the reason that high lattice energy released (energy released during the formation of solid metal hydrides from their corresponding ions, i.e., M⁺ and H^–) more than compensates the energy needed for the formation of H^– ions from H₂ gas.

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The process \(\frac{1}{2}\)H2(g) + e– → H– (g) is endothermic (AH = +151 kJmol-1), yet salt like hydrides are known. How do you account for this?

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