Question

What is the structural formula of lithium tetrahydroaluminate?
a.) $Al\left[ {LI{H_4}} \right]$
b.) $A{l_2}{\left[ {Li{H_4}} \right]_3}$
c.) $Li\left[ {Al{H_4}} \right]$
d.) $Li{\left[ {Al{H_4}} \right]_2}$

Answer 1

Hint: In order to solve this question, we will see some properties of the lithium tetrahydroaluminate and then will see its structure. It is an inorganic compound and a grey solid. It is a great reducing agent used for synthesis of esters, carboxylic acids and more.

Complete step by step solution:
The structural formula of lithium tetrahydrio aluminate is $Li\left[ {Al{H_4}} \right]$
$L{i^ + }\,{\left[ {\begin{array}{*{20}{c}}
  {}&{\begin{array}{*{20}{c}}
  H \\
  |
\end{array}}&{} \\
  H&{ - Al - }&H \\
  {}&{\begin{array}{*{20}{c}}
  | \\
  H
\end{array}}&{}
\end{array}} \right]^ - }$

Hence, the correct option is C.

Additional Information- LAH is a colorless solid but, due to contamination, commercial samples are usually gray. Recrystallization of diethyl ether can purify this material. A Soxhlet extractor is used for large-scale purifications. The impure gray material is usually used in synthesis because of its harmless impurities and the organic products can be easily separated. The material is pure and powdered, but its crystals are not large. In some commodities, mineral oil inhibits atmospheric humidity reactions, but it is usually packaged in water proof plastic bags. In organic synthesis this compound is used as a reduction in esters, carboxylic acids and amide in particular. The solid reactivates dangerously to water and releases gaseous hydrogen

Note: To solve these types of problems you need to learn about the chemical properties and structural properties of complex compounds. You need to learn about the naming of the complex compound. $Li\left[ {Al{H_4}} \right]$ is commonly abbreviated as LAH. It is a colorless solid. LAH is soluble in ethereal solutions and may decompose spontaneously due to presence of catalytic impurities in the water.