Module 3
1. Module 3
1.12. Page 4
Module 3—Electrochemical Reactions
Read
Metals that are more likely to react with the ions of other metals are considered to be more reactive or, using the terminology introduced in this lesson, are stronger reducing agents. A redox table is used to list oxidizing and reducing agents by their strengths. Read the lower half of page 569 to the end of the “Summary” section on page 571 of the textbook to learn more about the organization of a redox table.
Self-Check
SC 1. Complete “Practice” questions 1–3 and 5–10 on page 571 of the textbook.
Read
In SC 1 you were asked to develop a hypothesis about the design of a redox table and to test the redox table using the data available to you.
Read pages 572–574 of the textbook. Carefully work through “Sample problem 13.4” on page 573 and “Figure 6” in the margin of page 573 to understand the spontaneity rule, a general principle demonstrated by redox tables constructed in the manner described in this lesson. You may wish to refer to page 7 of the Chemistry Data Booklet on which an extended redox table is shown.
Self-Check
SC 2. Complete “Practice” questions 11–14 on page 573 of the textbook.
SC 3. Complete “Practice” question 20 on page 574 of the textbook.
Self-Check Answers
Contact your teacher if your answers vary significantly from the answers provided here.
SC 2.
Practice 11.
Co2+(aq) + 2 e- ↔ Co(s)
Zn2+(aq) + 2 e- ↔ Zn(s)
Mg2+(aq) + 2 e- ↔ Mg(s)
Practice 12.
Cu2+(aq) + 2 e- ↔ Cu(s)
2 H+(aq) + 2 e- ↔ H2(g)
Cd2+(aq) + 2 e- ↔ Cd(s)
Be2+(aq) + 2 e- ↔ Be(s)
Ca2+(aq) + 2 e- ↔ Ca(s)
Practice 13.
The spontaneity rule is based on empirical evidence from experimental results.
Practice 14.
Cl2(g) + 2 e- ↔ 2 Cl-(aq)
Br2(g) + 2 e- ↔ 2 Br-(aq)
Ag+(aq) + e- ↔ Ag(s)
I2(s) + 2 e- ↔ 2 I-(aq)
Cu2+(aq) + 2 e- ↔ Cu(s)
SC 3.
Practice 20.
a. spontaneous
b. non-spontaneous
c. non-spontaneous
d. spontaneous
e. spontaneous
f. spontaneous
Module 3: Lesson 2 Assignment
Retrieve your copy of the Module 3: Lesson 2 Assignment that you saved to your computer earlier in this lesson. Complete Part 2 of the Assignment. Save your work in your course folder. You will receive instructions later in this lesson on when to submit your completed Assignment to your teacher.
Reflect and Connect
RC 1. In the Get Focused section at the beginning of this lesson, three commonly used metals were identified: copper, silver, and gold. Examine the position of these metals on the large table of half-reactions shown in your Chemistry Data Booklet. How do the locations of these metals in the table correlate with the observations made in the Get Focused section?
Save your response in your course folder.
Module 3: Lesson 2 Assignment
Make sure you have completed both parts of the Lesson 2 Assignment:
- Part 1: Lab—Spontaneity of Redox Reactions
- Part 2: Lab Exercise 13.A on page 572 of the textbook
Submit your completed Module 3: Lesson 2 Assignment to your teacher.