1. Stoichiometric Calculations

2. It only looks hard.

3. Stoichiometric Calculations It only looks hard. Honest.

4. Stoichiometric Calculations K + H 2 O → KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 1: Balance the equation.

5. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 1: Balance the equation.

6. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 2: Ask yourself, “What do you know?”

7. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 2: Ask yourself, “What do you know?”

8. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 2: Ask yourself, “What do you know?” I know how many moles of K

9. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 3: Ask yourself, “What do you need to know?” I know how many moles of K

10. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 3: Ask yourself, “What do you need to know?” I know how many moles of K

11. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 3: Ask yourself, “What do you need to know?” I know how many moles of K I need to know moles of H 2

12. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 4: Use the equation to find the ratio of unknown to known

13. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 4: Use the equation to find the ratio of unknown to known moles H 2 = 1 moles K 2

14. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 5: multiply the known number by the ratio

15. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 5: multiply the known number by the ratio unknown known x known = unknown

16. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 5: multiply the known number by the ratio mol H 2 mol K x mol K = mol H 2

17. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 5: multiply the known number by the ratio 1 mol H 2 0.04 mol K x 2 mol K =0.02 mol H 2

18. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 6: the answer should have the same number of significant digits 1 mol H 2 0.04 mol K x 2 mol K =0.02 mol H 2

19. Stoichiometric Calculations 2 K + 2 H 2 O → 2 KOH + H 2 If you use 0.04 mol of K, how much H 2 will you produce? Step 6: the answer should have the same number of significant digits 1 mol H 2 0.04 mol K x 2 mol K =0.02 mol H 2

20. In-class work: a.Solve practice problems 9 & 10 on page 359. b.Choose a chemical equation from chapter 10. Don’t use one that has all the coefficients = 1. c.Write it as a problem similar to problem 9 or 10. d.Trade with someone. You solve theirs and they solve yours.