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F
T
The ideal gas laws need correction under conditions of high pressure and low temperature.
113. In an electrolytic cell, the anode
BECAUSE
anions migrate to the anode and
becomes positive and the cathode
cations migrate to the cathode.
becomes negative
T
T
The anode becomes positive because it loses electrons; therefore, anions migrate toward it and vice versa
for the cathode.
114. When a piece of Al is dropped into a
BECAUSE
Al is more readily oxidized than Mg.
1M solution of MgCl
2
, elemental Mg
appears
F
F
Mg is more readily oxidized (remember relative electron affinities) than Al; so elemental Al can not
reduce Mg
+2
to Mg. Elemental Mg can reduce Al
+3
.

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Lesson 10
300
w w w . p e t e r s o n s . c o m / a r c o
ARCO
■ SAT II Subject Tests
Part C
26. The correct answer is (E). Phosphoric acid has three protons it can donate; therefore, it can form
three anionic species.
27. The correct answer is (D). All the ions have noble gas configurations except Co
+2
.
28. The correct answer is (C). Using the formula V
1
· N
1
= V
2
· N
2
where V = volume and N = normality,
the volume of .3M H
2
SO
4
required is 250ml.
29. The correct answer is (B). Co
+3
is a strong oxidant: Co
+3
+ e
–
= Co
+2
ε° = 1.84V.
30. The correct answer is (E). Using Hund’s rule, a half-filled orbital is more stable than a full orbital.
The configuration of 3d
5
and 4s
1
maximizes the number of half-filled orbitals. Remember that 4s is
filled before 3d. Cr has no 4p electrons.