Question

20 balanced equation examples with name of elements

Answer 1

Balanced Equations

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As you have already learned earlier, mass can neither be created nor destroyed. This law applies to a chemical reaction too. This means that the total mass of elements in the products of a chemical reaction has to be equal to the total mass of the elements in the reactants. The number of atoms of each element remains the same, before and after a chemical reaction. For example, let’s look at the following chemical equation –

Zinc + Sulphuric acid → Zinc sulfate + Hydrogen

This is further simplified as –

Zn + H2SO4 → ZnSO4 + H2

Now, let us look at the number of atoms of each element on LHS and RHS –

Element Number of atoms in reactants (LHS) Number of atoms in products (RHS)

Zn 1 1

H 2 2

S 1 1

O 4 4

As you can see, the number of atoms of each element on LHS and RHS are the same. Therefore, this chemical equation is a ‘balanced equation’. Now, look at the following equation –

Fe +H2O → Fe3O4 +H2

If you notice, the number of atoms of each element are not the same on both sides of the arrow. Therefore, this is an ‘unbalanced’ equation. We can balance this equation using the following steps –

Step I

First, draw boxes around each formula without changing anything inside the boxes.

balanced equation

Step II

List the number of atoms of each element on either side of the arrow in the equation –

Element Number of atoms in reactants (LHS) Number of atoms in products (RHS)

Fe 1 3

H 2 2

O 1 4

Step III

To balance the above equation, let’s start with the compound with the maximum number of atoms i.e. Fe3O4. Now, in this compound select the element with the maximum number of atoms i.e. oxygen. As you can see, there are 4 oxygen atoms on the RHS, whereas there is only one oxygen atom on the LHS. Let’s try to balance the oxygen atoms –

Atoms of oxygen In reactants In products

(i) Initial 1 (in H2O) 4 (in Fe3O4)

(ii) To balance 1 x 4 4

Step IV

Now, let’s balance the hydrogen atoms in the equation –

Atoms of hydrogen In reactants In products

(i) Initial 8 (in 4H2O) 2

(ii) To balance 8 2 x 4

Therefore, we add 4 as a coefficient to H2 on the RHS. The equation will now be –

balanced equation

Step V

Now, you will find that only one element is left unbalanced i.e. Fe. Let’s try to balance that –

Atoms of iron In reactants In products

(i) Initial 1 (in Fe) 3 (in Fe3O4)

(ii) To balance 1 x 3 3

Therefore, we add 3 as a coefficient to Fe on the LHS –

balanced equation

Solved Examples for You

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Question: Write the balanced equations for the following chemical reactions –

HNO3 +Ca(OH)2 → Ca(NO3)2 + H2O

BaCl2 + Al2(SO4 )3 → BaSO4 + AlCl3

Zinc + Silver nitrate → Zinc nitrate + Silver

Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water

Solutions:

2HNO3 +Ca(OH)2 → Ca(NO3)2 + 2H2O

3BaCl2 + Al2(SO4 )3 → 3BaSO4 + 2AlCl3

Zn + 2AgNO3 → Zn(NO3)2 + 2Ag

Ca(OH)2 + CO2 → CaCO3 + H2O