Question

When $MgC{{l}_{2}}.6{{H}_{2}}O$ is strongly heated, then it forms:
A) $MgO$
B) $Mg{{(OH)}_{2}}$
C) $Mg(OH)Cl$
D) $MgC{{l}_{2}}$

Answer 1

Hint: The answer here is based upon the organic chemistry reaction which includes oxidation reaction taking place and the product of the oxidation reaction is usually the oxides. This fact gives you the required answer.

Complete Solution :
We have studied in our chapters of organic chemistry about the oxidation, reduction, elimination and many other reactions that make use of respective reagents to get the required products.
Let us now see what the oxidation reaction and the conditions for it are.
- Oxidation reaction generally makes use of high temperatures that is heat application and this reaction is the one in which loss of electron takes place that is the oxidation state of the atom or ion will be increased.
- Now, when hydrated magnesium chloride is heated it loses the water molecules at the first step that is out of six water molecules four molecules are released. The reaction is as shown below,:
\[MgC{{l}_{2}}.6{{H}_{2}}O\xrightarrow{\Delta }MgC{{l}_{2}}.2{{H}_{2}}O+4{{H}_{2}}O\]

- Now, since the compound is strongly heated, the further application of heat results in the oxidation process where the two moles of water molecule reacts chemically with magnesium chloride to give the oxide of magnesium that is:
\[MgC{{l}_{2}}.2{{H}_{2}}O\xrightarrow{{}}MgO+2HCl+{{H}_{2}}O\]

Thus, the product formed here contains magnesium oxide that is $MgO$ with two moles of an acid and one mole of water.
So, the correct answer is “Option A”.

Note: Note the fact that oxidation products need not always involve the oxygen atom in it, that is it does not always produce oxides. Oxidation is the increase in the oxidation state that is removal of the electrons from atoms.