1. Stoichiometry ElementMeasure

2. 2 H 2 + O 2  2 H 2 O 2 molecules of hydrogen react with every molecule of oxygen to produce 2 molecules of water 2 moles of hydrogen react with every mole of oxygen to produce 2 moles of water

3. 2 H 2 + O 2  2 H 2 O Multiply by 2 4 H 2 + 2 O 2  4 H 2 O 4 moles of hydrogen react with every 2 moles of oxygen to produce 4 moles of water Divide by 2 H 2 + 0.5 O 2  H 2 O 1 mole of hydrogen reacts with every 0.5 moles of oxygen to produce 1 mole of water

4. Pancake comparison 250 mL of pancake batter + 500 mL milk  6 How much pancake batter do I need if I only want to make 2 pancakes?

5. 2 H 2 + O 2  2 H 2 O How many moles of H 2 are required to produce 4 moles of H 2 O? How many moles of O 2 are required? 4 = 2x x = 4/2 x = 2 moles O 2

6. 2 H 2 + O 2  2 H 2 O How many moles of O 2 are required to produce 0.5 moles of H 2 O? 0.25 moles of O 2

7. 2 H 2 + O 2  2 H 2 O How many moles of O 2 are required to produce 7 moles of H 2 O? 3.5 moles of O 2

8. 2 H 2 + O 2  2 H 2 O What mass of O 2 and H 2 are required to produce 9 moles of H 2 O? n = m MM m n 144 g of O 2

9. 2 H 2 + O 2  2 H 2 O What mass of O 2 and H 2 are required to produce 9 moles of H 2 O? 2 12 9 4.5 18.18 g of H 2

10. 2 H 2 + O 2  2 H 2 O What mass of H 2 0 is present when 9 moles are produced? 2 12 9 94.5 162.18 g of H 2 O

11. 2 H 2 + O 2  2 H 2 O 4 g of H 2 react with what mass of O 2 in the above reaction?

12. 2 H 2 + O 2  2 H 2 O 4 g of H 2 react with what mass of O 2 in the above reaction? 2 12 31.68 g of O 2

13. C 3 H 8 + 5 O 2  3 CO 2 + 4 H 2 O 220 g of C 3 H 8 react in the above reaction. What mass of H 2 O is produced?

14. C 3 H 8 + 5 O 2  3 CO 2 + 4 H 2 O 220 g of C 3 H 8 react in the above reaction. What mass of H 2 O is produced? 153 4

15. Pb(NO 3 ) 2 + 2 NaI  PbI 2 + 2 NaNO 3 50 mL of a 0.5 mol/L solution of NaI reacts to produce how many grams of PbI 2 ? C = nVnV

16. Pb(NO 3 ) 2 + 2 NaI  PbI 2 + 2 NaNO 3 50 mL of a 0.5 mol/L solution of NaI reacts to produce how many grams of PbI 2 ? 121 2

17. Stoichiometry Steps 1.Write and balance the equation 2.Write the ratio of substances in moles on top of the equation 3.Convert the given information into moles (if necessary) 4.Complete a cross-multiplication to determine the number of moles of the substance in question 5.Convert the answer into the required units (e.g. grams) 6.Write out the answer to the question in correct units.