1. Molar Relationships

2. A balanced chemical equation can be interpreted in numbers of molecules, but generally chemists interpret equations as “mole-to-mole” relationships. 2H 2 (g) + O 2 (g) → 2H 2 O (l) In the equation above: 2 moles of hydrogen gas and 1 mole of oxygen gas produce 2 moles of liquid water.

3. Therefore: H 2 & O 2 have a 2:1 mole-to-mole ratio O 2 & H 2 O have a 1:2 mole-to-mole ratio H 2 & H 2 O have a 1:1 mole-to-mole ratio 2H 2 (g) + O 2 (g) → 2H 2 O (l) Molar Relationships

4. What are the mole-to-mole ratios in the chemical equation above? N 2 + 3H 2 → 2NH 3 Molar Relationships

5. Find the number of moles of NH 3 that can be formed from 4.8 mol H 2 using the balanced reaction below. N 2 + 3H 2 → 2NH 3 Molar Relationships 4.8 mol H 2 2 mol NH 3 3 mol H 2 x = 3.2 mol NH 3

6. Find the number of moles of LiNO 3 needed to produce 3.2 mol Pb(NO 3 ) 4 using the balanced reaction below. Pb(SO 4 ) 2 + 4LiNO 3  Pb(NO 3 ) 4 + 2Li 2 SO 4 Molar Relationships 3.2 mol Pb(NO 3 ) 4 4 mol LiNO 3 1 mol Pb(NO 3 ) 4 x = 12.8 mol LiNO 3

7. Practice Problems Grab your clicker! (& a calculator)

8. Consider the balanced chemical reaction: 2Fe + 3 H 2 S0 4 → Fe 2 (SO 4 ) 3 + 3H 2 How many moles of Fe are required to produce 9 moles of H 2 ? A. 9 moles B. 2 moles C. 4.5 moles D. 6 moles Question #1

9. Consider the balanced chemical reaction: 2Fe + 3 H 2 S0 4 → Fe 2 (SO 4 ) 3 + 3H 2 How many moles of Fe 2 (SO 4 ) 3 will be produced if we begin with 17 moles of Fe? A. 17 moles B. 8.5 moles C. 34 moles D. 11 moles Question #2

10. Consider the balanced chemical reaction: 2C 2 H 6 + 7O 2 → 6H 2 O + 4CO 2 How many moles of carbon dioxide are produced from 1 mole of C 2 H 6 ? A. 1 moles B. 2 moles C. 7 moles D. 8 moles Question #3

11. Consider the balanced chemical reaction: 2C 2 H 6 + 7O 2 → 6H 2 O + 4CO 2 How many moles of O 2 are required to produce 9 moles of H 2 O? A. 10.5 moles B. 6 moles C. 9 moles D. 7.5 moles Question #4

12. Consider the following chemical reaction: KOH + H 3 PO 4 → K 3 PO 4 + H 2 O How many moles of KOH are required to produce 12.5 moles of H 2 O? A. 2.5 moles B. 7.5 moles C. 9 moles D. 12.5 moles Question #5

13. Consider the following chemical reaction: KOH + H 3 PO 4 → K 3 PO 4 + H 2 O How many moles of H 3 PO 4 are required to produce 9 moles of H 2 O? A. 3 moles B. 6 moles C. 9 moles D. 7 moles Question #6