8.5 - Calculations based on Chemical Equations
8.5.1 - Mole-mole Calculations
Given the balanced chemical equation AND the number of moles of
any one of the reactants or products, the proportional number of moles of any
other reactant or product can be determined by using the appropriate stoichiometric mole ratio.
In the example below, you will be given the mole of one reactant (C2H5OH) and you will be asked to find
the mole of the other reactant (oxygen gas).
How many moles of oxygen gas is required to burn 3.60 moles
of ethyl alcohol, C2H5OH?
Here are the steps involved to answer this question:
Step 1: Identify the chemical equation
involved: a combustion reaction (review types of reactions, section
Step 2: Write the balanced chemical equation
(review balancing equations, section 8.3).
Step 3: Determine the stoichiometric ratio of
the substances that you are working with specifically between ethyl alcohol
Step 4: Calculate the number of moles of oxygen
by making the ratio specifically for 3.60 moles of ethyl alcohol.
Click here for a detailed look at my work.
Mole Method of Solving Stoichiometry Problems ..p250