Stoichiometry Stoichiometric Calculations C Johannesson Proportional relationships b

Stoichiometry Stoichiometric Calculations C. Johannesson

Proportional relationships b To make a PBJ sandwich, you need 2 slices of bread, 2 tablespoons of peanut butter, and 2 tablespoons of jelly. b If you have 15 slices of bread, and plenty of peanut butter and jelly, how many sandwiches could you make? C. Johannesson

Proportional Relationships b Stoichiometry • mass relationships between substances in a chemical reaction • based on the mole ratio b Mole Ratio • indicated by coefficients in a balanced equation 2 Mg + O 2 2 Mg. O C. Johannesson

Do Problems in packet C. Johannesson

Mole map C. Johannesson

Mole Map / Foldable C. Johannesson

Stoichiometry problems C. Johannesson

Stoichiometry Steps 1. Write a balanced equation. 2. Identify known & unknown. 3. Line up conversion factors. Mole ratio Molar mass - moles grams 4. Check answer. C. Johannesson

Mole to mole b How many moles of KCl. O 3 must decompose in order to produce 9 moles of oxygen gas? 2 KCl. O 3 2 KCl + 3 O 2 ? mol 9 mol O 2 2 mol KCl. O 3 3 mol O 2 C. Johannesson = 6 mol KCl. O 3

Do Problems in packet C. Johannesson

Mole to gram b. How many grams of calcium nitride are produced with 2. 5 moles of calcium? 3 Ca + N 2 Ca 3 N 2 2. 5 mol Ca 1 mol Ca 3 N 2 3 mol Ca 148. 26 g Ca 3 N 2 1 mol Ca 3 N 2 C. Johannesson = 123. 55 g Ca 3 N 2

Do Problems in packet C. Johannesson

Example b. Calculate the number of moles of ethane (C 2 H 6) needed to produce 10 g of water. 2 C 2 H 6 + 7 O 2 4 CO 2 + 6 H 2 O 10 g H 2 O 1 mol H 2 O 2 mole C 2 H 6 18. 02 g H 2 O 6 mole H 2 O C. Johannesson = 0. 19 mol C 2 H 6

Do Problems in packet C. Johannesson

D. Stoichiometry Problems b How many grams of silver will be formed from 12. 0 g copper? Cu + 2 Ag. NO 3 2 Ag + Cu(NO 3)2 12. 0 g ? g 12. 0 1 mol 2 mol 107. 87 g Cu Cu Ag g Ag = 40. 7 g 63. 55 1 mol Ag g Cu Cu Ag C. Johannesson

Do Problems in packet C. Johannesson