1. Predicting
Redox Reactions
9.3

2. Predicting Spontaneous Reactions Using the Standard Reduction Chart
Does Au3+ react with Cl-?
If it does write the spontaneous reaction.

3. The top reaction is written forward- reduction
The bottom reaction is written in reverse- oxidation
(Au e  Au(s)) 2
(2Cl-  Cl2(g) + 2e-) 3
2Au Cl-  3Cl2(g) Au(s)

4. Does Ag+ react with Br-?

5. nonspontaneous

6. Some ions are on both sides of the table and are oxidizing or reducing agents. For example:
Fe  Fe2+  Fe3+
Sn  Sn2+  Sn4+   
Cu  Cu+  Cu2+

7. Does Sn2+ react with Cr?

8. spontaneous 3 (Sn2+ + 2e-  Sn(s)) 2 (Cr(s)  Cr3+ + 3e-)
Check both
spontaneous 3
(Sn e-  Sn(s)) 2
(Cr(s)  Cr e-)
2Cr (s) Sn2+  2Cr Sn(s)

9. Can you keep HCl in a Cu container? Explain!

10. nonspontaneous

11. Can you keep HCl in a Cu container? Explain!
Yes, nonspontaneous.
H+ is a weaker oxidizing agent than Cu2+ and Cu+.

12. Can you keep HCl in a Zn container? Explain!

13. Spontaneous- no
H+ is a stronger oxidizing agent than Zn2+

14. Write the spontaneous reaction.
2H e  H2(g)
Zn(s)  Zn e-
2H Zn(s)  H2(g) + Zn2+

15. Can you keep HNO3 in a Au container? Explain!

17. Can you keep HNO3 in a Au container? Explain!
Yes, nonspontaneous.
HNO3 is a weaker oxidizing agent than Au3+.

18. Can you keep HNO3 in a Cu container? Explain!

19. Take the strongest ox agent- higher
Take the strongest red agent- lower

20. Can you keep HNO3 in a Cu container?
No, spontaneous.
HNO3 is a stronger oxidizing agent than Cu2+.
Write the spontaneous reaction.
NO H e-  NO(g) H2O x 2
Cu(s)  Cu e- x 3
2NO H Cu(s)  2NO(g) H2O Cu2+

21. nonspontaneous- both on same side
Does Au3+ react with Fe3+?

22. spontaneous- downhill
Does Fe3+ react with Pb?

23. nonspontaneous- uphill
Does Cl2 react with F-?

24. spontaneousdownhill
Does S2O82- react with Pb?

25. nonspontaneous- uphill
Does Cu2+ react with Br-?

26. spontaneous- downhill
Does Br2 react with Sn2+?

27. nonspontaneous- uphill
Does Pb2+ react with Fe2+?

28. spontaneous- downhill
Can you keep HCl in a Fe or a Ag container?
HCl → H Cl-
Yes
2H e- → H2(g)
Fe → Fe e- No
2H Fe → H2(g) Fe2+

29. Can you keep HNO3 in a Au or a Ag container?
Yes
NO H e- → NO(g) H2O
Ag → Ag e-
x 3 No
NO H Ag → NO(g) H2O Ag+