A chemical equation is a representation of any chemical reaction and the formation of new products. The substances which react to form new substances are called reactants and the new substances formed are called products. There is often loss or gain of energy during chemical reactions.
A chemical equation is represented in the following manner
Reactant 1+ Reactant 2+….. — — — — → Product 1+ Product 2+……
The direction of the arrow is always towards the products
Ex: Zn+2HCl — → ZnCl2+ H2
Balancing chemical equation means equalling the number of atoms of all the elements in the reactants side to the number of atoms of all the elements in the products side.
In the above reaction
1. the number of Zn atoms on both sides is 1
2. The number of hydrogen atom on both sides is 2
3. The number of chlorine atom on both sides is 2
Hence the reaction is balanced.
Rules for balancing chemical equation
Certain axiomatic rules , you need to follow while balancing the equations
1. Only coefficients can be added to balance the equation. The coefficients appear before the element to be balanced.
While balancing the equation according to lab report-
Fe2O3+ C — — -> Fe + CO2
We have just added the coefficients 2 and 3 to balance it, as mentioned below
2Fe2O3+ C — — -> Fe + 3CO2