1. Mass-Mass Stoichiometry If the mass of any reactant or product is known for a chemical reaction, it is possible to calculate the mass of the other reactants and products.

2. Sample Problem: How many grams of carbon dioxide (CO 2 ) would be produced by the combustion of butane (C 4 H 10 ) with 17.9 grams of oxygen (O 2 ) as shown in the following chemical equation? C 4 H 12 + O 2 → CO 2 + H 2 O Step 1: Balance the chemical equation 467 17.9 g ? Note: Write the value of the given substance over that substance and put a “?” over the required substance. Ignore everything else in the equation

3. The solving process involves the use of dimensional analysis 17.9 g ? C 4 H 12 + 7O 2 → 4CO 2 + 6H 2 O Step 2: Convert grams of given substance to moles 17.9 g O 2 1 mol O 2 32.0 g O 2 Step 3: Give ratio of moles required substance/given substance 4 mol CO 2 7 mol O 2 Step 4: Convert moles of required substance to grams 44.0 g CO 2 1 mol CO 2 Step 5: Cancel and solve =28.1 g CO 2

4. Practice Problems Try to work the next problems on the paper first. Then use the power point to check your work.

5. Practice Problem 1: What amount of barium chloride (BaCl 2 ) would be made by the reaction of 105 g of hydrochloric acid (HCl) with barium nitrate as the following equation shows? 105 g ? 2HCl + Ba(NO 3 ) 2  2HNO 3 + BaCl 2 Solve the above problem and check your answer below: 105.0 g HCl 1 mol HCl 36.5 g HCl 1 mol BaCl 2 2 mol HCl 208 g BaCl 2 1 mol BaCl 2 =299.2 g BaCl 2

6. Practice Problem 2: What amount of hydrogen (H 2 ) must react with 13.3 g oxygen (O 2 ) to completely consume the available oxygen and form water? ? 13.3 g 2H 2 + O 2  2H 2 O Solve the problem and then check your answer below. 13.3 g O 2 1 mol O 2 32 g O 2 2 mol H 2 1 mol O 2 2.02 g H 2 1 mol H 2 =1.68 g H 2

7. Practice Problem 3: How much sulfuric acid (H 2 SO 4 ) is required to produce 31.2 grams of silver sulfate (Ag 2 SO 4 )? ? 31.2 H 2 SO 4 + 2AgCl  Ag 2 SO 4 + 2HCl Solve the problem and then check your answer below. 31.2 g Ag 2 SO 4 1 mol Ag 2 SO 4 312 g Ag 2 SO 4 1 mol H 2 SO 4 1 mol Ag 2 SO 4 98.1 g H 2 SO 4 1 mol H 2 SO 4 =9.81 g H 2 SO 4