Chemistry - Oxidation and Reduction
Exam Duration: 45 Mins Total Questions : 30
Oxidation is also termed as
- (a)
electronation
- (b)
deelectronation
- (c)
protonnation
- (d)
deprotonnation
In the given reaction \(2Fe{ Cl }_{ 3 }+Sn{ Cl }_{ 2 }\longrightarrow 2Fe{ Cl }_{ 2 }+Sn{ Cl }_{ 4 }\) the substance which is reduced is
- (a)
Sn2+
- (b)
Fe3+
- (c)
Fe2+
- (d)
Sn4+
In the reaction \(Cu+{ SO }_{ 4 }^{ 2- }+4{ H }^{ + }\longrightarrow { Cu }^{ 2+ }+2{ H }_{ 2 }O+A\) the product A is
- (a)
SO2
- (b)
SO3
- (c)
S2-
- (d)
S4
In oxygen difluoride the oxidation number of oxygen is
- (a)
-2
- (b)
-1
- (c)
+2
- (d)
+1
The oxidation number of hydrogen in calcium hydride is
- (a)
+1
- (b)
-1
- (c)
+2
- (d)
+2
The equivalent weight of KMnO4 in neutral medium is
- (a)
31.6
- (b)
158
- (c)
52.66
- (d)
26.33
The oxidation number of iron in the complex \({ Na }_{ 4 }[Fe{ \left( CN \right) }_{ 5 }NOS]\) is
- (a)
0
- (b)
1
- (c)
2
- (d)
3
Equal volumes each of 1M solution containing FeCl3 and SnCl2 are mixed together, the resultant solution will contain
- (a)
Fe2+, Sn2+, Sn4+
- (b)
Fe2+, Fe3+, Sn2+
- (c)
Fe2+, Fe3+, Sn4+
- (d)
Sn2+, Sn4+, Fe3+
Which one of the following equations represents the change \(Mn{ O }_{ 4 }^{ - }\longrightarrow Mn{ O }_{ 2 }\) in basic solution?
- (a)
\(Mn{ O }_{ 4 }^{ - }+4{ H }_{ 2 }O+3e\longrightarrow Mn{ O }_{ 2 }+2{ H }_{ 2 }O+{ OH }^{ - }\)
- (b)
\(Mn{ O }_{ 4 }^{ - }+4{ OH }^{ - }\longrightarrow Mn{ O }_{ 2 }+2{ H }_{ 2 }O+{ 3e }\)
- (c)
\(Mn{ O }_{ 4 }^{ - }+4{ H }^{ + }-3e\longrightarrow Mn{ O }_{ 2 }+2{ H }_{ 2 }O\)
- (d)
\(Mn{ O }_{ 4 }^{ - }+4{ H }^{ + }\longrightarrow Mn{ O }_{ 2 }+2{ H }_{ 2 }O+3e\)
In a redox reaction, the oxidant
- (a)
shares electrons with the reductant
- (b)
gains electrons from the reductant
- (c)
transfers electrons to the reductant
- (d)
neither shares nor transfers electrons to the reductant
In which one of the following the oxidation number of sulphur is zero?
- (a)
H2SO3
- (b)
H2SO4
- (c)
H2SO5
- (d)
(CH3)2SO
In the reaction \(3CuS+2N{ O }_{ 3 }^{ - }+8{ H }^{ + }\longrightarrow 3{ Cu }^{ 2+ }+2NO+4{ H }_{ 2 }O+3S\) which one of the following statements is not correct?
- (a)
The oxidation number of nitrogen changes
- (b)
The oxidation number of nitrogen does not undergo any change
- (c)
The oxidation number of sulphur changes
- (d)
The oxidation numbers of sulphur and nitrogen both change
In the reaction \(C{ l }_{ 2 }+{ 2I }^{ - }\longrightarrow { I }_{ 2 }+2C{ I }^{ - }\)which one of the following statements is correct?
- (a)
Iodide ions are reduced to iodine
- (b)
Chlorine is oxidised to chloride ion
- (c)
Chlorine is oxidised to chloride and iodide ions are oxidised to iodine
- (d)
Iodide ions are oxidised to iodine and chlorine is reduced to chloride ions
The oxidation numbers of oxygen in H2O and H2O2 are
- (a)
- 1 and - 1
- (b)
- 2 and - 1
- (c)
- 2 and - 2
- (d)
- 1 and - 2
In the reaction \({ 2I }^{ - }+{ Cl }_{ 2 }\longrightarrow { I }_{ 2 }+2C{ l }^{ - }\) the reductant is
- (a)
I-
- (b)
Cl2
- (c)
I2-
- (d)
Cl-
In alkaline medium manganese in MnO4- ion is reduced to MnO2 . The change in its oxidation number is
- (a)
2
- (b)
3
- (c)
5
- (d)
7
CO2 is
- (a)
an oxidising agent
- (b)
a reducing agent
- (c)
a dehydrating agent
- (d)
a bleaching agent
Maximum oxidation state of phosphorus is found in
- (a)
H3PO4
- (b)
H4P2O7
- (c)
H3PO5
- (d)
H4P2O6
The charge on coblt in \([Co\left( { CN }_{ 6 } \right) ]^{ -3 }\) is
- (a)
- 3
- (b)
- 6
- (c)
+ 3
- (d)
+ 6
Which one of the following is the strongest oxidising agent?
- (a)
F2
- (b)
Cl2
- (c)
Br2
- (d)
I2
In which of the following compounds iron has the lowest oxidation state?
- (a)
FeSO4 (NH4)2SO4.6H2O
- (b)
K4Fe(CN)6
- (c)
K3 Fe (CN)6
- (d)
Fe(CO)5
Select the compound in which chlorine is assigned the oxidation number + 7.
- (a)
HClO4
- (b)
HClO2
- (c)
HClO3
- (d)
HCl
Oxidation number of P in \({ K }H_{ 2 }{ PO }_{ 2 }\) in
- (a)
+ 1
- (b)
+ 2
- (c)
+ 3
- (d)
+ 5
If three electrons are lost by a metal ion M+3 , its final oxidation number would be
- (a)
zero
- (b)
- 3
- (c)
+ 6
- (d)
NONE OF THESE
Oxidation numbr of oxygen atom in potassium peroxide is
- (a)
0
- (b)
\(????-\frac { 1 }{ 2 } \)
- (c)
- 4
- (d)
- 2
The colour of K2Cr2O7 changes from red orange to lemon orange yellow on treatment with aqueous KOH because of
- (a)
reduction of Cr (VI) to Cr (III)
- (b)
formation of chromium hydroxide
- (c)
conversion of dichromate ion to chromate
- (d)
oxidation of potassium hydroxide to potassium peroxide
Which substance is serving as a reducing agent in the following reaction?\(14{ H }^{ + }+{ Cr }_{ 2 }{ O }_{ 7 }^{ 2- }+3\quad Ni\longrightarrow 2{ Cr }^{ 3+ }+7{ H }_{ 2 }O+3{ Ni }^{ 2+ }\)
- (a)
\({ H }_{ 2 }O\)
- (b)
Ni
- (c)
\({ H }^{ + }\)
- (d)
\({ Cr }_{ 2 }{ O }_{ 7 }^{ 2- }\)
A 2.5 mol of hydrazine N2H4 loses 25 mole of electrons being converted to a new compound X. Assume that all of the nitrogen appeas in the new compound, what is the oxidation state of nitrogen in compound X?
- (a)
- 1
- (b)
- 2
- (c)
+ 3
- (d)
+ 4
When KMnO4 acts as an oxidising agent and ultimately forms MnO4-1, MnO2, Mn2O3, Mn2+ then the number of electrons transferred in each case respectively is
- (a)
4 , 3, 1, 5
- (b)
1, 5, 3, 7
- (c)
1, 3, 4, 5
- (d)
3, 5, 7, 1
Which of the following is a redox reaction?
- (a)
\(Nacl+KN{ O }_{ 3 }\longrightarrow Na{ NO }_{ 3 }+Kcl\)
- (b)
\(Ca{ C }_{ 2 }{ O }_{ 4 }+2HCl\longrightarrow CaC{ l }_{ 2 }+{ H }_{ 2 }{ C }_{ 2 }{ O }_{ 4 }\)
- (c)
\(Mg\left( OH \right) _{ 2 }+2N{ H }_{ 4 }Cl\longrightarrow Mg{ Cl }_{ 2 }+2N{ H }_{ 4 }OH\)
- (d)
\(Zn+2AgCN\longrightarrow 2Ag+Zn\left( CN \right) _{ 4 }\)