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TASK 1 – Bronsted-Lowry acids & bases
1
4
7
Acid = H2O, base = NH3
Acid = HCl, base = CH3COOH
+
Acid = H , base = HCO3
2
5
8
Acid = HCl, base = H2O
Acid = HCl, base = NH3
Acid = H2SO4, base = HNO3
3
6
Acid = HCOOH, base = KOH
Acid = HCO3 , base = OH
TASK 2 – pH of strong acids
1
2
3
4
a
a
a
a
0.70
-4
2.82 x 10
1.48
0.56
b
b
b
b
1.30
0.0100
0.80
0.39
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c
c
c
c
1.10
0.0501
0.10
0.10
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d
d
d
d
-0.30
-3
1.58 mol dm
0.82
-0.31
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TASK 3 – pH of strong bases
1
2
3
4
a
a
a
a
13.18
2.00
12.30
13.70
b
b
b
b
12.70
0.0158
13.20
14.25
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c
c
c
c
13.60
-3
0.501 mol dm
13.00
12.22
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TASK 4 – Strong acid + strong base
1
6
2.00
2
1.48
new pH = 1.00, increase by 0.30
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3
7
13.12
4
13.15
new pH = 1.60, decrease by 11.58
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5
1.60
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3
TASK 5 – a mixture
1
2
3
4
5
a 13.48
a 6.63
a 0.40
a 12.52
13.74
b
b
b
b
0.70
c
-0.48
+
still neutral as [H ] = [OH ]
12.00
0.93
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d
12.70
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TASK 6 – pH of weak acids
1
2
3
4
a 2.51
b
2.76
c
1.87
-5
-3
-3
a 5.00 x 10 b
5.50 x 10 mol dm
a ethanoic acid
b
propanoic acid
-5
-3
4.79 x 10 mol dm
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TASK 7 – Reactions of weak acids
-
-
-
-
1)
HA = 1.5, OH = 0, A = 2.5
2)
HA = 3.4, OH = 0, A = 2.6
-
-
3)
HA = 0, OH = 0.10, A = 0.15
4)
HA = 0.15, OH = 0, A = 0.15
5)
HA = 0.0075, OH = 0, A = 0.0025
6)
HA = 0, OH = 0.0275, A = 0.0125
7)
HA = 0.0002, OH = 0, A = 0.0008
-
-
-
-
-
-
-
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TASK 8 – Weak acid + strong base
1
12.30
2
4.54
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3
4.76
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4
2.26
5
13.92
6
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3.14
8
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TASK 9 – Another mixture
1
6
0.70
4.76
2
7
2.19
5.24
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3
8
13.60
13.30
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4
1.22
5
12.30
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TASK 10 – Sketching pH curves
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TASK 11 – Titration calculations
1
2
3
-3
a 0.0752 mol dm
-3
a 0.050 mol dm
0.113 g
4
87.8
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b
b
5
-3
3.01 g dm
-3
7.10 g dm
2
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6
K
7
87.7%
8
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90.8%
13
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TASK 12 – Buffer solution calculations
1
2
3
4
a
a
a
a
3.35
b
4.72
4.35
b
3.57
47.9 g
b
0.0113 g
pH = 11.29, change = 4.29
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c
4.77
b
pH = 4.60, change = 0.02
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TASK 13 – A mixture of pH calculations
1
7
12
0.70
2
1.00
+
6.63, neutral as [H ] = [OH ]
12.63
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3
8
13.70
4.45
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4
9
1.60
0.88
5
10
1.93
12.52
6
11
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4.20
4.06
18
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