2c practice key - Practice Midterm Exam#1 Chem 2C(B Fall...

Practice Midterm Exam #1 -- Chem 2C (B)
Fall 2007 Name
POTENTIALLY USEFUL INFORMATION and a PERIODIC CHART
are given on the last two pages of this exam
Problem (possible
Points) Points
1-10 (40)
11 (12)
12 (8)
13 (20)
14 (20)
TOTAL (100)

Chem 2C(B) – Fall 07 2
Practice Midterm 1 Name
2
Each multiple choice question is worth 4 points. Circle the BEST answer. Only ONE
answer will be graded--if two are circled--the answer will be counted as WRONG!
1. Consider the following reaction:
Cd(s) + 2AgCl(s) ––> Cd
2+
(aq) + 2Ag(s) + 2Cl
—
(aq)
In this reaction, the reducing agent is
(a) Cd(s)
(b) AgCl(s)
(c) Cd
2+
(d) Ag(s)
(e) Cl
–
(aq)
2. The equilibrium constant for the reaction 2Hg(l) + 2Cl
—
(aq) + Ni
2+
(aq) Æ
Ni(s) +Hg
2
Cl
2
(s) is 5.6 x 10
-20
at 25 ˚ C. Calculate E ˚ for a cell utilizing this
reaction.
(a) —0.25 V
(b) +0.57 V
(c) +1.14 V
(d) —0.57 V
(e) —1.14 V
3. The standard potential of the Ag
+
/Ag electrode is +0.80 V and the standard
potential of the cell Fe(s)|Fe
2+
(aq) ||Ag
+
(aq)|Ag(s)
is +1.24 V. What is the standard potential of the Fe
2+
/Fe electrode?
(a) +0.44 V
(b) +2.04 V
(c) —0.88 V
(d) —2.04 V
(e) —0.44 V
4. Which species will reduce Cr
3+
but not Mn
2+
?
(a) In
2+
(b) Al (c) Fe (d) Zn (e) Sn

Chem 2C(B) – Fall 07 3
Practice Midterm 1 Name
3
5. Given: SO
4
2—
(aq) Æ H
2
SO
3
(aq), acidic solution.
When this half-reaction is balanced, both H