Q.How can saline hydrides remove traces of water from organic compounds?

Ionic (saline) hydrides such as calcium hydride ($CaH_2$) or sodium hydride ($NaH$) react readily and completely with water, even in very small (trace) amounts, because the hydride ion H⁻ is strongly basic/reducing and reacts essentially instantaneously with water:

When such a hydride is added to an organic solvent/compound that contains only trace moisture, the hydride consumes exactly that trace water in this reaction, converting it into insoluble metal hydroxide (which can be filtered off) and dihydrogen gas (which simply escapes as a gas). …

Recall that ionic hydrides react vigorously and completely with water (CaH2 + 2H2O → Ca(OH)2 + 2H2); reason that adding a hydride to a moist organic c …

• Forgetting to note that the reaction goes essentially to completion (not equilibrium) — this completeness is exactly why it is effective for removing even trace moisture. …