Question

i forgot how to balance a chemical equation. can someone give me some examples? a simple one and then a more complex one would be preferrable.

Answer 1

Example: the reactants are glucose (C6H12O6) and oxygen (O2) and the products are carbon dioxide (CO2) and water (H2O)
The unbalanced chemical equation is C6H12O6 + O2 → CO2 + H2O

Now, a set of equations must be formulated (between the reactant and product side) in order to balance each element in the reaction.

6a = c (for carbon); 6a = d (for hydrogen); 6a + 2b = 2c + d (for oxygen)

a = 1

c = 6a = 6*1 = 6

d = 6a = 6

Substituting the values of a,c, and d in the equation 6a + 2b = 2c + d, the value of ‘b’ can be obtained as follows:

6*1 + 2b = 2*6 + 6

2b = 12; b = 6

Therefore, aC6H12O6 + bO2 → cCO2 + dH2O becomes:

C6H12O6 + 6O2 → 6CO2 + 6H2O