Question

What is the oxidation number of Li in $LiAl{H_4}$ ?

Answer 1

Hint : LAH stands for lithium aluminium hydride, which is an inorganic substance having the chemical formula $LiAl{H_4}$ . It's a solid grey colour. Finholt, Bond, and Schlesinger found it in 1947. This chemical is employed in organic synthesis as a reducing agent, particularly for the reduction of esters, carboxylic acids, and amides. The solid reacts violently with water, producing gaseous hydrogen ( ${H_2}$ ). For hydrogen storage, certain similar derivatives have been explored.

Complete Step By Step Answer:
The oxidation state of an element that has not been mixed is zero. This is true regardless of the element's structure: $Xe,C{l_2},{S_8}$ , and massive carbon or silicon structures all have an oxidation state of zero. In a neutral substance, the total of all the oxidation states of all the atoms or ions is zero. The charge on an ion is equal to the total of the oxidation states of all the atoms in the ion. A negative oxidation state is ascribed to the more electronegative element in a material. A positive oxidation state is ascribed to the less electronegative element. Keep in mind that electronegativity is highest at the top-right corner of the periodic table and falls toward the bottom-left corner.
Metal hydrides include hydrogen, as do substances such as sodium hydride, NaH. The hydrogen ion, H-, occurs here as a hydride ion. The charge on a simple ion like hydride determines its oxidation state, which is -1 in this case. The total of the oxidation states of a neutral chemical, on the other hand, is zero. Because Group 1 metals in their compounds always have an oxidation state of +1, the hydrogen must have an oxidation state of -1 (+1 -1 = 0).
Oxidation number of Li = x
Oxidation number of Al = + 3
Oxidation number of H = - 1
X + 3 + 4(−1)=0
x+3−4=0
x−1=0
$\Rightarrow x = 1$ .

Note :
In redox processes, oxidation states make it easier to figure out what is being oxidised and what is being reduced. However, it would be beneficial to study and be familiar with the following ideas for the sake of this introduction:
In terms of electron transport, there is a difference between oxidation and reduction.