Redox Reactions CBSE Questions & Answers

Redox Reactions

This is Chemistry Class 11 Redox Reactions CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

A metal in a compound can be displaced by another metal in the uncombined state. Which metal is a better reducing agent in such a case?

A
Both are same in reducing capacity
B
the reduced metal is a better reducing agent than the reducing metal
C
better reducing agent is the one that loses more electrons
Correct
D
better reducing agent is the one that loses less electrons

Displacement of hydrogen from cold water is done by

A
all transition elements
B
superoxides
C
all alkaline earth metals
D
all alkali metals
Correct

Fractional Oxidation Number exists because

A
the average oxidation state of the element is divided by two
B
the element is present in different oxidation states
Correct
C
middle carbon in such elements has always zeo oxidation state
D
electrons are never shared/transferred in that element

The strength of a reductant/oxidant in redox systems can be determined

A
by taking into consideration the different oxidation states of the atom in the element
B
by taking into consideration only half reactions involving reduction
C
by the titration method using a redox sensitive indicator
Correct
D
by taking into consideration only half reactions involving oxidation

One of the following has application in electrode processes and cells

A
half reactions involving oxidation
B
half reactions involving reduction
C
the concept of redox reactions
Correct
D
the different oxidation states of the atom in the element

\({\text{Z}}{{\text{n}}^{{\text{2}} + }}/{\text{Zn}}\) represents

A
oxidised form of Zinc
B
oxidation number of +2 of Zinc
C
redox couple
Correct
D
reduced form of Zinc

In Daniell cell, direction of current is

A
opposite to the direction of electron flow
Correct
B
towards anode
C
in the same direction of electron flow
D
towards centre

The flow of current is possible in Daniel cell only

A
if the zinc and copper rods are connected by a salt bridge only
B
if there is a potential difference between the copper and zinc electrodes
Correct
C
if the transfer of electrons does take place directly from Zn to Cu2+
D
if the zinc and copper rods are connected by the platinum wire only

In oxygen difluoride \(\left( {{\text{O}}{{\text{F}}_{\text{2}}}} \right)\) and dioxygen difluoride\(\left( {{{\text{O}}_{\text{2}}}{{\text{F}}_{\text{2}}}} \right)\), the oxygen is assigned an oxidation number of

A
+2 and +4
B
+2
C
+4 and +3
D
+2 and +1
Correct

Oxidation number of \(\left( {\frac{1}{2}} \right)\) is assigned to oxygen atom in

A
peroxides
B
when oxygen is bonded to fluorine
C
when oxygen is bonded to metals
D
superoxides
Correct

Assign oxidation number to P in \({\text{Na}}{{\text{H}}_{\text{2}}}{\text{P}}{{\text{O}}_{\text{4}}}\)

A
+6
B
5.0
Correct
C
+1
D
+4

Assign oxidation number to S in \({\text{KAl }}{\left( {{\text{S}}{{\text{O}}_{\text{4}}}} \right)_{\text{2}}}.{\text{12 }}{{\text{H}}_{\text{2}}}{\text{O}}\)

A
+12
B
+4
C
+5
D
6.0
Correct

If an excess of \({{\text{P}}_{\text{4}}}\) is treated with \({{\text{F}}_{\text{2}}}\), then_____will be produced wherein the oxidation number of P is +3. The compound is

A
\({\text{P}}{{\text{F}}_{\text{5}}}\)
B
\({\text{P}}{{\text{F}}_{\text{3}}}\)
Correct
C
\({\text{P}}{{\text{F}}_{\text{6}}}\)
D
PF

Which of the following is not an example of redox reaction?

A
\({\text{BaCl2 }} + {\text{ H2SO4 }} \to {\text{ BaSO4 }} + {\text{ 2HCl}}\)
Correct
B
\({\text{Fe2O3 }} + {\text{ 3CO }} \to {\text{ 2Fe }} + {\text{ 3CO2}}\)
C
\({\text{CuO }} + {\text{ H2 }} \to {\text{ Cu }} + {\text{ H2O}}\)
D
\({\text{2K }} + {\text{ F2 }} \to {\text{ 2KF}}\)

Electrochemical processes for extraction of highly reactive metals and non-metals involves one of the following. Choose the most appropriate option.

A
reaction with inert gases
B
reduction processes
C
redox processes
Correct
D
oxidation processes