1. Mole Bridge HW 5-3

2. HW 5-3 #1 1 mole 12 g 0.25 moles 0.50 moles 0.33 moles 0.75 moles 3.0 g4.0 g 6.0 g 9.0 g

3. HW 5-3 #1 2.00 moles 2.50 moles 3.00 moles 24 g 18 g 36 g

4. How to Use the Mole Bridge Two conversion factors: 1 mole 1 mole 1 mole 6.022 x 10 23 atomic mass (g) 6.022 x 10 23 atomic mass (g)

5. The Actual Bridge over River Mole or “under”

6. Example: What is the mass in grams of 9.34 moles of Fe? 9.34 mol Fe 9.34 mol Fe (55.8 g Fe) (1 mole Fe) = 521 g 3 Sig Fig Note: SF of final answer should match SF of original given (Molar Mass SF should have at least as many SF as given).

7. HW 5-3 Part 1 moles → grams 1) What is the mass in grams of 0.521 MOLES of Ni (atomic #28)? 1) What is the mass in grams of 0.521 MOLES of Ni (atomic #28)? 0.521 mol Ni (1 mole Ni) (58.69 g Ni) = 30.6 g

8. HW 5-3 Part 1 moles → grams 2) What is the mass in grams of 2.49 moles of SO 3 ? SO 3 2.49 mol SO 3 (1 mole SO 3 ) (80.07 SO 3 g) = 199 g S: 1 x 32.07= 32.07 O: 3 x 16.00= 48.00 80.07 g/mol

9. HW 5-3 Part 2 grams → moles 3) 3) 26.2 g Au (1 mole Au) (196.97 g Au) = 0.133 mol

10. HW 5-3 Part 2 grams → moles 4 ) What is the number of moles in 1.271 grams of ethanol, C 2 H 5 OH? C 2 H 5 OH 1.271 g C 2 H 5 OH C 2 H 5 OH (1 mole C 2 H 5 OH) C 2 H 5 OH (46.08 g C 2 H 5 OH) = 0.02759 g C 2 : 2 x 12.01= 24.02 H 6 : 6 x 1.01 = 6.06 O: 1 x 16.00= 16.00 46.08 g/mol

11. HW 5-3 Part 3 moles → atoms or molecules 5) 5) 0.0015 moles Cu (6.022 x 10 23 atoms Cu) (1 mole Cu) = 9.0 x 10 20 atoms Cu

12. HW 5-3 Part 3 moles → atoms or molecules 6) 1.25 x 10 -2 moles Pb(CH 3 CO 2 ) 2 (6.022 x 10 23 molecules) (1 mole Pb(CH 3 CO 2 ) 2 ) = 7.53 x 10 21 molecules Pb(CH 3 CO 2 ) 2

13. HW 5-3 Part 3 moles → atoms or molecules 6) 3.312 x 10 24 atoms Se (6.022 x 10 23 atoms) (1 mole Se ) = 5.500 moles Se

14. How many ATOMS are present in 104.49 g of Bi? 104.49 g Bi 104.49 g Bi (208.98 g Bi) (1 mole Bi) (6.022 x 10 23 atoms Bi) (1 mole Bi) = 3.0110 x 10 23 atoms Bi

15. How many MOLECULES are present in 6.37 g of CO? 6.37 g CO 6.37 g CO (28.01 g CO) (1 mole CO) (6.022 x 10 23 molecules CO) (1 mole CO) = 1.37 x 10 23 molecules CO C: 1 x 12.01= 12.01 O: 1 x 16.00= 16.00 28.01 g/mol

16. What is the mass in grams of 1.804 x 10 24 atoms of Zr? 1.804 x 10 24 atoms Zr (91.22 g Zr) (1 mole Zr) = 273.3 g Zr (6.022 x 10 23 atoms Zr)

17. What is the mass in grams of 4.03 x 10 24 molecules of C 6 H 6 ? 4.03 x 10 24 molecules C 6 H 6 (78.12 C 6 H 6 g) (1 mole C 6 H 6 ) = 52.3 g C 6 H 6 (6.022 x 10 23 molecules C 6 H 6 ) C 6 : 6 x 12.01= 72.06 H 6 : 6 x 1.01= 6.06 78.12 g/mol

18. How many C atoms and H atoms are present in 10 molecules of methane, CH 4 ? C: 1 C: 1 H: 4 H: 4

19. How many C atoms and H atoms are present in 10 molecules of methane, CH 4 ? C: 10 C: 10 H: 40 H: 40

20. How many C atoms and H atoms are present in 1000 molecules of methane, CH 4 ? C: 1000 C: 1000 H: 4000 H: 4000

21. How many C atoms and H atoms are present in 6.022 x 10 23 molecules of methane, CH 4 ? C: 6.022 x 10 23 C: 6.022 x 10 23 H: 4 (6.022 x 10 23 ) = 2.409 x 10 24 H: 4 (6.022 x 10 23 ) = 2.409 x 10 24

22. How many C atoms and H atoms are present in 7.089 x 10 23 molecules of methane, CH 4 ? C: 7.089 x 10 23 C: 7.089 x 10 23 H: 4 C atoms/molecules (7.089 x 10 23 molecules) = 2.836 x 10 24 H: 4 C atoms/molecules (7.089 x 10 23 molecules) = 2.836 x 10 24