What Is Stoichiometry And Balancing Equations?

Stoichiometry is one of the main topics of chemistry because it is used out all through chemistry. It is defined as the calculation of the relationship between reactants and products in chemical reactions. Stoichiometry is written as equations. For example, I+2S = IS2. In this equation, we see numbers before the compounds/elements. They are referred to as stoichiometric coefficients. The purpose of these numbers is to balance a chemical equation to comply with the law of conservation of mass.

The law of conservation of mass states that the mass in a system cannot be destroyed or created. We use stoichiometric coefficients to make sure that the number of atoms of the reactants is equivalent to that of the number of atoms of the products.

Take the equation Pb(OH)4+H2SO4→Pb(SO4)2+H2O
Reactant Side:
H(hydrogen):6
Pb(lead): 1
O(oxygen): 8
S(sulfur): 1
Product Side:
H:2
Pb: 1
O: 9
S: 2
To balance this equation, we need the same number of atoms for each element on both sides. To do that, we need to add a 2 before sulfuric acid(H2SO4) and a 4 before water(H2O).

Pb(OH)4+2(H2SO4)→Pb(SO4)2+4(H2O)

Reactant Side:
H(hydrogen):8
Pb(lead): 1
O(oxygen): 12
S(sulfur): 2
Product Side:
H:8
Pb: 1
O: 12
S: 2

This way the total on both sides for hydrogen is 8, lead is 1, oxygen is 8, and sulfur is 2. Though it is sometimes tedious, it involves a lot of trial and error to equate the number of atoms on both sides. I hope you were able to take away something from this.

Picture Source: chem4kids.com