Here's how it works:
* Balanced Chemical Equation: A balanced chemical equation shows the relative amounts of reactants and products in a chemical reaction.
* Stoichiometric Coefficients: These are the numbers in front of each chemical formula in a balanced equation. They represent the number of moles of each substance involved in the reaction.
Example:
Consider the combustion of methane:
CH₄ + 2O₂ → CO₂ + 2H₂O
* 1 mole of methane (CH₄) reacts with 2 moles of oxygen (O₂) to produce 1 mole of carbon dioxide (CO₂) and 2 moles of water (H₂O).
How to calculate the molar mass used up:
1. Identify the stoichiometric coefficients: In the example above, the coefficient for methane is 1, and the coefficient for oxygen is 2.
2. Determine the molar mass of each reactant: The molar mass of methane (CH₄) is 16 g/mol, and the molar mass of oxygen (O₂) is 32 g/mol.
3. Multiply the molar mass by the stoichiometric coefficient:
* Methane: 16 g/mol * 1 = 16 g
* Oxygen: 32 g/mol * 2 = 64 g
Therefore, 16 grams of methane will react with 64 grams of oxygen in this reaction.
Key Point: The stoichiometric coefficients in a balanced chemical equation are essential for determining the molar masses of reactants used up in a reaction and for calculating the amount of products that will be formed.
