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Molar Ratios. By Elise Rippelmeyer. Molar Ratios are…. A molar ratio is a ratio between the number of moles of any two species involved in a chemical reaction. For Example:. 2H 2 + O 2 2H 2 O 2 mol 1 mol 2 mol Six Molar ratios can be written:
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Molar Ratios By Elise Rippelmeyer
Molar Ratios are… • A molar ratio is a ratio between the number of moles of any two species involved in a chemical reaction.
For Example: • 2H2 + O2 2H2O 2 mol 1 mol2 mol Six Molar ratios can be written: 2 mol H2 2 mol H2 1 mol O2 1 mol O2 2 mol H2O 2 mol H2 1 mol O2 2 mol H2O 2 mol H2O 2 mol H2O2 mol H2 1 mol O2
Why? • We use the mole ratio to convert the number of moles of one substance to the corresponding number of moles of another substance in a chemical reaction.
For Example: • To calculate the number of moles of H2O that can be obtained from 4.0 mol of O2, we use the mol ratio 2 mol H2O/1 mol O2. 2 mol H2O (4.0 mol O2) = 8.0 mol H2O 1 mol O2
3 Basic Steps 1. Convert the quantity of starting substance to moles 2. Convert the moles of starting substance to moles of desired substance 3. Convert the moles of desired substance to the units specified in the problem