Chemistry Question

Name ____________________________Acid-Base Quiz (1)
1. Identify the acid and base on the left side of the following equations and identify their
conjugate species on the right side.
a.
HPO42- (aq)
+
H2O (l)
HO- (aq)
b.
HPO42- (aq)
+
H2O (l)
PO43- (aq)
H2PO41- (aq)
+
+
H3O+
2. a. If a solution has a hydronium concentration [H3O+] of 6.8 X 10-10 M, what is the
hydroxide concentration [HO-]? Show all work!
b. What is the pH of the solution?
3. Complete the following table:
[ H3O+]
[ HO-]
pH
1 X 10 -11 M
7.53 X 10 -4 M
5.7 X 10 -3M
8.0
Acidic, Basic, or Neutral
4. If 135.0 mL of a NaOH solution is used to neutralized 75 mL of a 2.5 M phosphoric
acid (H3PO4) solution, what is the molarity of the NaOH solution?
H3PO4(aq) +
3 NaOH (aq)
Na3PO4 (aq) + 3 H2O (l)
5. How many grams of NaBr react when combined with 0.65 mL of a 2.0 M Cr2(SO4)3
solution?
6 NaBr + Cr2(SO4)3
3 Na2SO4
+ 2 CrBr3
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Radioactivity
Half-life Practice Problems
1. How many half lives and minutes will it take for a 230.4 uCi Kr-79 sample to decay to
under 10 uCi? Kr-79 has a half life if 11.5 min.
2. How many microCuries (uCi) were in an original sample, if after 46.4 days, there are
26 uCi of a Ba-131 sample. The half life for Ba-131 is 11.6 days?
3. How many half lives and minutes will it take for a 200 uCi Au-198 sample, with a half
life of 64.8 hr, to decay to 10 uCi?
Radioactivity Quiz (2)
Name __________________________
1. Complete the following nuclear equations:
a.
b.
249
97
Bk
+
4
2
He
+
0
-1
e
96
41
Nb
+
1
0
n
+
4
2
He
2. Write the complete nuclear equation for the beta emitter Samarium-151.
3. After 11.6 years how much of a 136 mg sample of Polonium-208 remains, if the isotope
has a half-life of 2.9 years?
Chapter 8 Practice Quiz Answer Key
1. Identify the acid and base on the left side of the following equations and identify their
conjugate species on the right side.
a.
HCO3- (aq)
Base
b.
H3O+ (aq)
Acid
+
+
H2O (l)
!HO- (aq)
Acid
Base
NO3- (aq)
!HNO3 (aq)
Base
Acid
+
H2CO3 (aq)
Acid
+
H2O (aq)
Base
2. a. If a solution has a hydroxide concentration [HO-] of 7.6 X 10-9 M, what is the
hydronium concentration [H3O+]? Show all work!
1 X 10 -14 M = [H3O+] 7.6 X 10-9 M
1 X 10 -14 M = [H3O+]
7.6 X 10-9 M
1.3 X 10 -6 M
b. What is the pH of the solution?
= [H3O+]
pH 5.89
3. Complete the following table:
[ H 3O+]
[ HO-]
pH
Acidic, Basic, or Neutral
1 X 10 -8 M
1 X 10 -6 M
8.0
Basic
1 X 10 -11 M
1 X 10 -3 M
11.0
Basic
3.5 X 10 -4 M
2.9 X 10 -11 M
3.46
Acidic
1.5 X 10 -12M
6.7 X 10 -3M
11.82
Basic
4. If 37.0 mL of a 0.25 M sulfuric acid (H2SO4) solution is used to neutralized 25 mL of
a KOH solution, what is the molarity of the KOH solution?
H2SO4(aq) +
2 mol KOH
1 mol H2SO4
x
0.25 mol H2SO4
1 L H2SO4
2 KOH (aq)
x
1 L H2SO4
1000 mL H2SO4
x
K2SO4 (aq) +
37.0 mL H2SO4
1
x
1000 mL KOH
1 L KOH
2 H2O (l)
x
1
25 mL KOH
=
0.74M KOH
5. How many grams of NaCl react when combined with 25 mL of a 0.5 M Al2(SO4)3
solution?
6 NaCl + Al2(SO4)3
3 Na2SO4
+ 2 AlCl3
0.5 moL Al2(SO4)3
1 L Al2(SO4)3
58.5 g NaCl
6 moL NaCl
25 mL Al2(SO4)3
x
x
x
x
1 moL NaCl 1 moL Al2(SO4)3
1 L Al2(SO4)3
1000 mL Al2(SO4)3
1
=
4 g NaCl
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