Question

How would you identify the missing coefficient in the balanced equation and classify the type of reaction?
$Mg{{(OH)}_{2}}+{{H}_{2}}S{{O}_{4}}\to MgS{{O}_{4}}+{{H}_{2}}O$

Answer 1

Hint: Write down the no. of atoms at reactant side and no. of atoms at product side and further try to make the numbers equal which will result in balanced equation. Also, neutralization reaction occurs when an acid reacts with a base and gives salt with water as products.

Complete step-by-step answer:A balanced chemical equation is the usage of chemical symbols to show the molecules and atoms in a chemical reaction. The reactants are represented on the left hand side of the equation and the products are on the right hand side. Coefficients give information about number of molecules involved and the subscripts gives us information about the number of atoms present in each molecule.
Let us write down the chemical equation as follows:-
-$Mg{{(OH)}_{2}}+{{H}_{2}}S{{O}_{4}}\to MgS{{O}_{4}}+{{H}_{2}}O$
Now let us write down the no. of atoms on each side of the reaction:-
Reactant side: - Product side:-
Mg= 1 Mg= 1
H= 4 H= 2
O= 6 O= 5
S= 1 S= 1
As we can see that, no. of Mg and S atoms are the same on both sides but no. of H and O atoms are different. Therefore, to equalize the no. of H and O atoms, we will multiply ${{H}_{2}}O$ with 2.
-$Mg{{(OH)}_{2}}+{{H}_{2}}S{{O}_{4}}\to MgS{{O}_{4}}+2{{H}_{2}}O$
Now let us write down the no. of atoms on each side of the reaction:-
Reactant side: - Product side:-
Mg= 1 Mg= 1
H= 4 H= 4
O= 6 O= 6
S= 1 S= 1
Since all the atoms on both the sides are same, therefore $Mg{{(OH)}_{2}}+{{H}_{2}}S{{O}_{4}}\to MgS{{O}_{4}}+2{{H}_{2}}O$ is the balanced chemical equation. Hence the missing coefficient is 2.
A neutralization reaction is a reaction in which an acid and a base react quantitatively to produce salt and water. In this reaction, we can generally see the combination of ${{H}^{+}}$ and $O{{H}^{-}}$ions to form ${{H}_{2}}O$ as product. When a strong acid reacts with the strong base, neutralization leads to exothermic reaction as heat is released.
$Mg{{(OH)}_{2}}+{{H}_{2}}S{{O}_{4}}\to MgS{{O}_{4}}+{{H}_{2}}O$
As we can see that, in the above reaction $Mg{{(OH)}_{2}}$ which is base reacts with ${{H}_{2}}S{{O}_{4}}$(an acid), to give $MgS{{O}_{4}}(salt)\text{ and }{{H}_{2}}O$ as products.
Therefore, the above reaction can be categorized as a neutralization reaction.

Note: Whenever we multiply molecules with some number, always write down the no. of atoms on both sides because we multiply the number with not only a particular atom but with all the atoms that molecule is composed of.