To determine the relative acidity and bond enthalpy of and , let's examine both:

Acidic Strength:

The acidity of hydrides increases as we move down the group in the periodic table. This is because the bond strength between hydrogen and the central atom decreases, making it easier for the hydrogen ions to dissociate. Therefore, , being further down the group than , is more acidic:

Bond Enthalpy:

Bond enthalpy refers to the energy required to dissociate a bond. The bond enthalpy decreases down the group due to weaker bonds forming as the atomic size increases.
Hence, has a higher bond enthalpy compared to :

Thus, is indeed less acidic than , but it has a higher bond enthalpy for dissociation.