WorksheetsOxidation and Reduction
Total questions: 30
Worksheet time: 47mins
Substances that lose electrons easily and are oxidized in a chemical reaction are ____________.
reducing agents
coloring agents
oxidizing agents
neutralizing agents
analytical agents
What is the oxidation number of Nitrogen in HNO3
-7
-5
+5
+7
+2
Identify the species reduced in the following reaction.
Fe(s) + 2 Ag+(aq) → Fe2+(aq) + 2 Ag(s)
Fe
Ag
none of these
None of the above
The below reaction is an example of _________reaction.
F2 → 2 F- + 2 e-
Oxidation
Reduction
Neutralization
decomposition
combustion
Find the oxidation number of Ca in CaH2
-2
-4
+2
+4
0
Oxidation is....
Gain of electrons
Loss of electrons
Both the loss and gain of electrons
None of these
Reduction is....
Gain of electrons
Loss of electrons
Both the loss and gain of electrons
None of these
What is the oxidation state of Nitrogen in N2 (g)?
4
6
2
0
Oxidation involves
gaining electrons; gaining oxygen
losing electrons; losing oxygen
gaining electrons; losing oxygen
losing electrons; gaining oxygen
Identify the substance that is reduced in the reaction between copper(II) ion and magnesium.
Cu2+ + Mg → Cu + Mg2+
Cu2+
Mg
Cu
Mg2+
Gaining oxygen is an example of...
oxidation
reduction
In a redox reaction, the species reduced
gains electrons and is the oxidizing agent
loses electrons and is the oxidizing agent
loses electrons and is the reducing agent
gains electrons and is the reducing agent
Mg → Mg2+ + 2e–
In a reaction, copper is reduced; its number of electrons has:
Increased
Decreased
Remained Constant
Varies Randomly
2Ca(s) + O2(g) --> 2CaO(s), calcium is __________
In a redox reaction, spectator ions...
become oxidised
become reduced
remain unchanged
4Fe + 3O2 --> 2Fe2O3
In the reaction
4 NH3 + 5 O2 → 4 NO + 6 H2O
the oxidation number of nitrogen changes from
–2 to –3
–2 to +3
–3 to –2
–3 to +2
What is the oxidation number of chromium in K2Cr2O7 ?
+12
+2
+3
+6
In which substance does hydrogen have an oxidation number of zero?
LiH
H2O
H2S
H2
In which substance is the oxidation number of Cl equal to +1?
Cl2
Cl2O
AlCl3
HClO2
What is the oxidation state of phosphorus in the
compound Na3PO3?
0
-3
+3
+5
In which compound does hydrogen have an oxidation state of –1?
NaH
HCl
H2O
NH3
Oxygen has an oxidation number of –2 in
O2
NO2
Na2O2
OF2
Given the reaction:
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
The oxidation number of Zn(s) increases because it
loses electrons
gains electrons
loses protons
gains protons
Which change in oxidation number represents reduction?
–1 to +1
–1 to –2
–1 to +2
–1 to 0
Given the reaction:
F2(g) + 2 Br–(aq) → Br2() + 2 F–(aq)
Which species is reduced?
F2(g)
Br–(aq)
Br2 (l)
F–(aq)
