Q.Give the equation for the preparation of lithium aluminium hydride, $\text{LiAlH}_4$, from lithium hydride and aluminium chloride. Why is $\text{LiAlH}_4$ valuable in synthetic chemistry, and why must it be handled under strictly anhydrous conditions?

[!TLDR] LiAlH4 is made from LiH + AlCl3 in dry ether; it is a powerful hydride-delivering reducing agent that reacts violently with water, so anhydrous handling is essential. [!ANSWER] $4\text{LiH}+\text{AlCl}_3\rightarrow \text{LiAlH}_4+3\text{LiCl}$; LiAlH4 is valuable because it delivers hydride ($\text{H}^-$) to r …

Lithium aluminium hydride is prepared under strictly anhydrous conditions, typically in dry diethyl ether as solvent, from lithium hydride and aluminium chloride:\n$4\text{LiH} + \text{AlCl}_3 \longrightarrow \text{LiAlH}_4 + 3\text{LiCl}$\nIts value in synthetic chemistry stems from the highly hydridic, nucleophilic character of the four hydrogen atoms bonded to aluminium in the $[\text{AlH}_4]^-$ anion: $\text{LiAlH}_4$ readily delivers a hydride ion ($\text{H}^-$) to electrophilic centres, most notably the carbonyl carbon of aldehydes, ketones, esters and carboxylic acids, reducing them efficiently to the corresponding alcohols (and reducing many other functional groups, such as nitriles and epoxides, as well). This makes it one of the most powerful and widely relied-upon reducing agents available to synthetic organic chemists. Precisely because its hydride ions are so reactive, $\text{LiAlH}_4$ must be handled under strictly anhydrous conditions: it reacts with even trace moisture, and violently (potentia …

Write the balanced LiH/AlCl3 preparation equation, then explain LiAlH4's reducing power via hydride delivery and the safety r …

Forgetting to balance the equation (4 LiH / 3 LiCl); describing LiAlH4 as an ox …