# Stoichiometry - Balance

Stoichiometry - The "art" of chemical measurements - the laws according to which substance unite to form chemical compounds. Stoichiometry is the relationship between the weights of the reactants and the products of a chemical reaction.

### Balance Example

In a balanced chemical equation, the coefficients of the reactants and products are equal to the mole ratio.

CH4 + O2 > CO2 + H2O     ---- balance ---->     CH4 + 2O2  =  CO2 + 2H2O

The mole ratio of oxygen to carbon dioxide is 2 :1

### Stoichiometry Example

Question: How many grams of water will be produced if  0.729 grams of methane reacts with oxygene.

Answer:  0.729 grams of methane  = 0.0454 moles. As we see from the balanced equation, the reaction will produce the double amount of H2O :         0.0454 moles * 2 = 0.0908 moles

Calulating we get:   18g/mole* 0.0908 mole = 1.63739 grams of H2O

### How solve Stoichiometry example using CHEMIX

Question: How many grams of water will be produced if  0.729 grams of methane reacts with oxygene.

1)  In CHEMIX push the balance button

2)  Insert the unbalanced equation in the unbalanced equation text field.

CH4 + O2 > CO2 + H2O

3) Argument CH4 by  0.279g  (0.279 grams)

0.279gCH4 + O2 > CO2 + H2O

4) Calculate.