Mole Ratio.pptx

Mole Ratio

1. ENGAGE

2. Aluminum metal reacts with iron (II) oxide powder to produce aluminum oxide solid and iron metal. Write and balance the chemical equation: + 3Fe + 3Fe  

3. A balanced chemical equation shows what reactants combine to form what products . It also shows the numerical relationships between the reactants and products

4. It also shows the numerical relationships between the reactants and products STOICHIOMETRY

5. A common type of stoichiometric relationship is the  mole ratio , which relates the amounts in moles of any two substances in a chemical reaction. Balanced equations and mole ratios

6. We can write a mole ratio for a pair of substances by looking at the coefficients in front of each species in the balanced chemical equation.  Balanced equations and mole ratios

7. EXAMPLE: + 2Fe +   Using this ratio, we could calculate how many Al moles end are needed to fully react with a certain amount of  , or vice versa. In general, mole ratios can be used to convert between amounts of any two substances involved in a chemical reaction.  

8. Using mole ratios to calculate mass of a reactant Consider the following  unbalanced  equation: NaOH + → +   How many grams of  NaOH  are required to fully consume  3.10  grams of   

9. SOLUTION 1.Balance the chemical equation. 2NaOH + →2 +  

10. SOLUTION 2NaOH + →2 +   Step 2: Convert known reactant mass to moles In order to relate the amounts  ​  and NaOH,  using a mole ratio we first need to know the quantity of ​  in  moles . We can convert the 3.10 grams of  ​ to moles using the molar mass of  ​ (98.08 g/mol):  

11. SOLUTION 2NaOH + →2 +   Step 3 : Use the mole ratio to find moles of other reactant

12. SHORTCUT SOLUTION Be sure to pay extra close attention to the units if you take this approach, though!

13. ACTIVITY