Balancing chemical equations

To learn how to balance chemical equations,you need to know the law of conservation of matter which states that the mass of a closed system of substances will remain constant regardless of the processes acting inside the system.Remember,matter can change form but never can it be created or destroyed.To simplify this,the mass of reactants and products must be equal always.

Lets now look at how you can balance chemical equations.

FIRST STEP

Write down the reactants and products of the chemical reaction.Ensure that reactants are on the left and products on the right.

SECOND STEP

Look at the different atoms present on both sides.Count them one by one.For example,

NaOH + HCl --> NaCl + H₂O

In this case,Na=1 on the reactant side and Na=1 on the product side,H=2 on the reactant and H=2 on the product side and so on.

THIRD STEP

Change the coefficients of the reactants or products to try to match the number of atoms on the opposite side.

Zn + 2HCl --> ZnCl₂ + H₂

EXAMPLE

Balance the equation below.

Mg + HCl --> MgCl₂ + H₂

1.To balance the equation,lets start by writing down the equation.

Mg + HCl --> MgCl₂ + H₂

2.Having done that,count the number of the different atoms on both sides.

Mg + HCl --> MgCl₂ + H₂

Reactants: Mg=1,Cl=1 and H=1.

Products: Mg=1,Cl=2 and H=2.

3.Change the coefficients of those that do not match,I'll start by changing the coefficient of the HCl to 2.

Mg + 2HCl --> MgCl₂ + H₂

This will now give us,

Reactants: Mg=1,Cl=2 and H=2.

Products: Mg=1,Cl=2 and H=2.

There you have it,the equation is balanced.The 2 changed the number of atoms for both hydrogen and chlorine,it works just like in algebra.However,if we have 2H₂O,the 2 will multiply with the subscript 2 on hydrogen and the 1 subscript on Oxygen,so you shall have 2 atoms of oxygen and 4 atoms of hydrogen.

EXAMPLE

Balance the equation below.

CH₄ + O₂ --> CO₂ + H₂O

1.CH₄ + O₂ --> CO₂ + H₂O

Reactants: C=1,O=2 and H=4.

Products: C=1,O=3 and H=2.

2.CH₄ + O₂ --> CO₂ + 2H₂O

Reactants: C=1,O=2 and H=4.

Products: C=1,O=4 and H=4.

3.CH₄ + 2O₂ --> CO₂ + 2H₂O

Reactants: C=1,O=4 and H=4.

Products: C=1,O=4 and H=4.

Simple is'nt it??? Thats all for now,drop your comments in the comment box below for more information or if you have any questions.Practice makes perfect,attempt more questions.