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Red-Ox

Total questions: 20

Worksheet time: 18mins

Name
Class
Date
1.

The equations below all show redox reactions.

Which oxide is oxidised in these reactions?

a)

Fe2O3

b)

CO

c)

ZnO

d)

NO

2.

Which change is an oxidation?

a)

FeO to Fe2O3

b)

Fe2O3 to FeO

c)

H2O2 to H2O

d)

H2O to H2

3.
Is calcium oxidized or reduced in the following reaction? 
2CaO--> 2Ca + O2
a)
Oxidized
b)
Reduced
4.
In the reaction
2Ca(s) + O2(g) --> 2CaO(s), calcium is __________
a)
Reduced
b)
Synthesized
c)
Oxidized
d)
None of the above
5.
What substance is oxidized in the following reaction?
4Fe + 3O2 --> 2Fe2O3
a)
Iron
b)
Fluorine
c)
Oxygen
6.

Which compound has manganese with oxidation number +6?

a)

K2MnO4K_2MnO_4

b)

KMnO4KMnO_4

c)

MnO2 MnO_{2\ }

d)

MnCl2 MnCl_{2\ }

7.
     In the reaction Zn + H2O --> ZnO2 + H2
 which element, if any, is oxidized? 
a)
Zinc
b)
Hydrogen
c)
Oxygen
d)
None
8.
If an atom loses electrons during a chemical reaction, the atom was:
a)
Oxidized
b)
Reduced
c)
Neutralized
d)
Precipitated
9.
What is oxidation number of Fe in FeO ?
a)
+2
b)
-2
c)
0
d)
+1
10.
What is oxidation number of H in CaH2?
a)
+1
b)
-1
c)
0
d)
+2
11.
What is oxidation number of Cr in Cr2O72-?
a)
-2
b)
+2
c)
+6
d)
+12
12.
What is the oxidation number of N in NO2-1?
a)
-3
b)
+4
c)
-2
d)
+3
13.

In the reaction Zn + 2HCl --> ZnCl2 + H2

which element, is oxidized?

Dalam persamaan Zn + 2HCl --> ZnCl2 + H2

unsur manakah telah dioksidakan?

a)

Zinc

Zink

b)

Hydrogen

Hidrogen

c)

Chlorine

Klorin

d)

None

Tiada

14.

Br2 + 2KI ----> 2KBr + I2

Which substance is oxidising agent?

Bahan manakah agen pengoksidaan

a)

Bromine water

Air bromin

b)

Potassium iodide

Kalium iodida

c)

Potassium bromide

Kalium bromida

d)

Iodine

Iodin

15.

Zn + CuSO4 ----> ZnSO4 + Cu

Which substance is oxidising agent?

Bahan manakah agen pengoksidaan?

a)

Zn

b)

Zn2+

c)

Cu

d)

Cu2+

16.

Which equation represents a redox reaction?

a)

NaOH + HNO3 → NaNO3 +H2O

b)

2AgNO3 + Zn → Zn(NO3)2 + 2Ag

c)

2NaCl + Pb(NO3)2 → PbCl2 + 2NaNO3

d)

CaCO3 + 2HCl → CaCl2 + H2O + CO2

17.

Consider the following reaction.

NO3 (aq) + Cu (s) → NO (g) + Cu2+ (aq)

Which statement is correct?

a)

Cu (s) is the reducing agent because it loses electrons.

b)

Cu (s) is the reducing agent because it gains electrons.

c)

Cu (s) is the oxidizing agent because it loses electrons.

d)

Cu (s) is the oxidizing agent because it gains electrons.

18.

What is the oxidizing agent in the following reaction?

Zn (s) + Cu2+ (aq) Zn2+ (aq) + Cu (s)

a)

Zn (s)

b)

Cu2+ (aq)

c)

Zn2+ (aq)

d)

Cu (s)

19.

Which substance is the reducing agent?

2Fe2+(aq) + Cl2 (aq) →2Fe3+(s) +2Cl- (aq)

a)

Fe2+

b)

Cl2

20.

Which element is oxidised in the reaction Zn + 2HCl  \rightarrow   ZnCl2 + H2  \

a)

Zinc

b)

Hydrogen

c)

Chlorine

d)

None