The alkali metals form salt-like hydrides by the direct synthesis at elevated temperature. The thermal…
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?
Key Idea : Small anion forms stable compounds with small cation.
The thermal stability of alkali metal hydrides decreases as :
$\mathrm{LiH} > \mathrm{NaH} > \mathrm{KH} > \mathrm{RbH} > \mathrm{CsH}$
because the size of cation increases as :
$\mathrm{Li}^{+} < \mathrm{Na}^{+} < \mathrm{K}^{+} < \mathrm{Rb}^{+} < \mathrm{Cs}^{+}$