What is Balancing Equation?

What is chemical reaction?
Answer, A chemical reaction is a process by which one set of chemicals is transformed into a new set  of chemicals.

A chemical equation uses standard chemicals symbols to describe the changes occurring during a reaction.

Any substance which react is called reactant and the results are called products.
For eg,
            H2+O2----------H2O
Hydrogen and Oxygen combine to form Water.But the equation is not balanced .

There are 2 oxygen atoms on the reactant side of the equation, but only one on the product side. If we place a 2 in front of the water on the product side, we will balance the oxygens.

H2+O2-------------2H2O

We now need to balance the hydrogens

 Place a 2 before the hydrogens on the reactant side of the equation

2H2 + O2 ---------2H2O

Balanced

Note: Diatomic molecules

Equation for formation of water included hydrogens and oxygens with subscript 2.

Other elements which occur in this way are Nitrogen, Fluorine, Chlorine, Bromine and Iodine.

These elements occur naturally as diatomic (meaning 2 atoms) molecules

The stoichiometric coefficients multiplying the chemical formulas tell you the relative numbers of moles of each substance that reacts or is produced in a chemical reaction.

Therefore, we can conclude from the balanced equation for water that 2 moles of hydrogen and one mol of oxygen combine to form water.

A chemical equation may also tell you what physical state the reactants and products are in. The following state symbols are used:

s (solid)

l (liquid)

g (gas)

aq (aqueous solution)

These are found as subscripts after each reactant and product.

Example

Balance the following equation:

Na(s) + H2O(l)  NaOH(aq) + H2(g)

Step 1: How many atoms of each element are present on the reactant and product side?

Reactants

Products

Na

H

O

1

2

1

Na

H

O

1

3

1

A chemical equation may also tell you what physical state the reactants and products are in. The following state symbols are used:

s (solid)

l (liquid)

g (gas)

aq (aqueous solution)

These are found as subscripts after each reactant and product.

Example

Balance the following equation:

Na(s) + H2O(l)  NaOH(aq) + H2(g)

Step 1: How many atoms of each element are present on the reactant and product side?

Reactants

Products

Na

H

O

1

2

1

Na

H

O

1

3

1

Step 2: Add state symbols

2Na(s) + 2H2O(l)  2NaOH(aq) + H2(g)

Questions

Balance the following equations:

(a) P2O5(s) + H2O(l)  H3PO4(aq)

Answer: P2O5(s) + 3H2O(l)  2H3PO4(aq)

If we may learn  this table so it will easy for balancing equation;