12C AB + Redox 1 homework due 14/10/16
1.
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%
NAME:
What is the oxidation number of chlorine in the ClO3– ion?
A
–1
B
+4
C
+5
D
+6
(Total 1 mark)
2.
Which of these reactions is not a redox reaction?
A
Mg(NO3)2(s) → MgO(s) + 2NO2(g) + ½O2(g)
B
HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)
C
Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s)
D
Cl2(aq) + 2Br–(aq) → 2Cl–(aq) + Br2(aq)
(Total 1 mark)
The Westlands School
1
12C AB + Redox 1 homework due 14/10/16
3.
(a)
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%
NAME:
Define reduction in terms of change in oxidation number.
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
The reaction between solid sodium halides and concentrated sulphuric acid changes as the
group is descended.
(i)
NaCl
Complete the balancing of the equation for the reaction of sodium bromide with
concentrated sulphuric acid.
+
H2SO4
→ NaHSO4
+
2NaBr + ……H2SO4 → ……NaHSO4
……H2O
8NaI
+
9H2SO4
→ 8NaHSO4 +
HCl
+
……SO2
H2S
+ 4I2
+
+
……Br2
+
4H2O
(1)
(ii)
Write the oxidation numbers of sulphur in the following:
H2SO4
..................................
NaHSO4 ..................................
SO2
..................................
H2S
..................................
(2)
The Westlands School
2
12C AB + Redox 1 homework due 14/10/16
(iii)
/27
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NAME:
Use the changes in oxidation number of sulphur in the reactions in (i) to show that
the halides become more powerful reducing agents as the group is descended.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 6 marks)
The Westlands School
3
12C AB + Redox 1 homework due 14/10/16
/27
%
NAME:
4.
The Westlands School
4
12C AB + Redox 1 homework due 14/10/16
/27
%
NAME:
5.
The Westlands School
5
12C AB + Redox 1 homework due 14/10/16
The Westlands School
/27
%
NAME:
6