<u>Answer:</u>
Free element is balanced at last.
We start to balance which occurs in fewer places, first.
Balancing requires Trial and error method
<u>Balancin</u>g is making the number of atoms of each element same on both the sides (reactant and product side).
To find the number of atoms of each element we multiply coefficient and the subscript
For example
contains
5 × 1 = 5,Ca atoms and
5 × 2 = 10, Cl atoms
If there is a bracket in the chemical formula
For example
we multiply coefficient
subscript
number outside the bracket.......... to find the number of atoms
(Please note: 3 is the coefficient, and if there is no number given then 1 will be the coefficient )
So
3 × 3 = 9, Ca atoms
3 × 1 × 2 = 6, P atoms
3 × 4 × 2 = 24, O atoms are present.
So
Let us balance the equation given

(Unbalanced)
Reactant side - Number of atoms of each element - Product side
1 - Ba - 1
2 - Cl - 1
2 - H - 1
1 - S - 1
4 - O - 4
So we see here H and Cl are not balanced
So by changing the coefficient of HCl as 2 we will have

(Balanced)
Reactant side - Number of atoms of each element - Product side
1 - Ba - 1
2 - Cl - 2
2 - H - 2
1 - S - 1
4 - O - 4
So we see the number of atoms of each element is same on both the sides.
Hence the equation is balanced !!!!!!!!!!