Exam 1-solutions - Version 573 Exam 1 Laude(52390 This...

Version 573 – Exam 1 – Laude – (52390) 1
This print-out should have 29 questions.
Multiple-choice questions may continue on
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before answering.
001 6.0 points
What would be the pH of a solution of hypo-
bromous acid (HOBr) prepared by dissolving
9.7 grams of the acid in 20 mL of pure wa-
ter (H
2
O)? The Ka of hypobromous acid is
6.0 points
Rank following salts from most to least solu-
ble:
BiI K
sp
= 7 . 7 × 10
− 19
Cd
3
(AsO
4
)
2
K
sp
= 2 . 2 × 10
− 33
AlPO
4
K
sp
= 9 . 8 × 10
− 21
CaSO
4
K
sp
= 4 . 9 × 10
− 5
1. AlPO
4
< BiI < Cd
3
(AsO
4
)
2
< CaSO
4
correct
Molar solubility can be approximated by
taking the n
th
root of the K
sp
where n is the
number of ions in the salt. Doing so results in
approximate molar solubilities of 10
− 10
, 10
− 7
,
10
− 11
and 10
− 3
for bismuth iodide, cadmium
arsenate, aluminum phosphate and calcium
sulfate, respectively. Arranging these from
least to greatest produces: AlPO
4
< BiI <
4
.
003 6.0 points
Determine the molar solubility of calcium
chloride (CaCl
2
) if
1. 9 correct
2. 5
3. 1
4. 13
5. 10.5

Version 573 – Exam 1 – Laude – (52390) 2
005 6.0 points
Consider the following exothermic reaction:
CaO( s ) + CO
2
( g ) ←→ CaCO
3
( s )
In response to a decrease in temperature, the
system would:
006 6.0 points
Consider the reaction,
Na
+
( aq ) + Cl
−
( aq ) ←→ NaCl( aq )
The equilibrium constant, K , is 2. If the
concentrations of Na
+
, Cl
−
and NaCl are 2, 2
and 10 M, respectively, which of the following
would occur?