Lithium hydride can be used to prepare other useful hydrides. Beryllium hydride is one of them. Suggest a route for the preparation of beryllium hydride starting from lithium hydride. Write chemical equations involved in the process.
Beryllium cannot react with dihydrogen like other alkaline earth metals to form beryllium hydride. Lithium hydride on the other hand is formed by heating with dihydrogen at 1073K. Steps to form beryllium hydride from lithium hydride are as follows.
Lithium hydride reacts with anhydrous aluminium chloride in presence of ether to form LiAlH4, lithium aluminium hydride.
LiH + Al2Cl6→ 2LiAlH4 + 6LiCl
LiAlH4 reacts with BeCl2 to form BeH2.
2BeCl2 + LiAlH4→ 2BeH2 + LiCl + AlCl3