Redox Reactions | JEE Main Chemistry Chapter Wise Question Papers

Q 1 :

In which of the following reaction, the underlined substance has been reduced?

$\underline{CO} + CuO \to \underline{{CO}_{2}} + Cu$
$\underline{CuO} + 2 HCl \to \underline{{CuCl}_{2}} + H_{2} O$
$4 \underline{H_{2} O} (g) + 3 Fe \to 4 \underline{H_{2}} (g) + {Fe}_{3} O_{4}$
$\underline{C} + 4 {HNO}_{3} \to \underline{{CO}_{2}} + 2 H_{2} O + 4 {NO}_{2}$

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(3)

1) $\overset{+ 2}{CO} \to \overset{+ 4}{{CO}_{2}}$

2) $\overset{+ 2}{CuO} \to \overset{+ 2}{{CuCl}_{2}}$

3) $\overset{+ 1}{H_{2} O} \to \overset{0}{H_{2}}$

4) $\overset{0}{C} \to \overset{+ 4}{{CO}_{2}}$

Only in (3), O.N. of hydrogen decreases from +1 to 0 and hence $H_{2} O$ gets reduced to $H_{2}$ .

Q 2 :

The correct group of halide ions which can be oxidized by oxygen in acidic medium is _______

$F^{-}$ only
$I^{-}$ only
$B r^{-}$ & $I^{-}$ only
$C l^{-}$ , $B r^{-}$ , $I^{-}$ only

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(2)

$only I^{-} is oxidized by O_{2} based on SRP values$

Q 3 :

Identify disproportionation reaction

$C H_{4} + 2 O_{2} \to C O_{2} + 2 H_{2} O$
$C H_{4} + 4 C l_{2} \to C C l_{4} + 4 H C l$
$2 F_{2} + 2 O H^{-} \to 2 F^{-} + O F_{2} + H_{2} O$
$2 N O_{2} + 2 O H^{-} \to N O_{2}^{-} + N O_{3}^{-} + H_{2} O$

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(4)

$2 N O_{2} + 2 O H^{-} \to N O_{2}^{-} + N O_{3}^{-} + H_{2} O$

Q 4 :

Column-I and Column-II contains four entries each. Entries of Column-I are to be matched with some entries of Column-II. One or more than one entries of Column-I may have the matching with the same entries of Column-II.

Column-I Column-II

(A) Very dilute solution of HCl (P) $O_{2}$ evolved at anode

(B) Very dilute solution of NaCl (Q) $H_{2}$ evolved at cathode

(C) Concentrated solution of NaCl (R) ${Cl}_{2}$ evolved at anode

(D) Aqueous ${AgNO}_{3}$ (S) Ag deposition at cathode

A → P, Q; B → R, Q; C → Q, R; D → P, S
A → P, Q; B → P, Q; C → Q, R; D → P, Q
A → Q, R; B → R, Q; C → Q, R; D → P, S
A → P, Q; B → P, Q; C → Q, R; D → P, S

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(4)

Electrolysis of dilute/concentrated NaCl: Water is reduced at the cathode to give hydrogen gas and chloride ion is oxidized at the anode (due to overpotential of oxygen) to give chlorine gas.

Electrolysis of dilute HCl: $H^{+}$ is reduced at the cathode and chloride ion is oxidized at the anode (due to overpotential of oxygen) to give chlorine gas.

Electrolysis of concentrated ${AgNO}_{3}$ : Silver ion is reduced at the cathode to deposit silver and water is oxidized at the anode to give oxygen gas.

Q 5 :

Assertion: $N a_{2} C r_{2} O_{7}$ cannot be used as a primary standard in titrations.

Reason: $N a_{2} C r_{2} O_{7}$ is hygroscopic in nature.

Assertion is True, Reason is true: Reason is the correct explanation for Assertion.
Assertion is true, Reason is true: Reason is not the correct explanation for Assertion.
Assertion is True, Reason is False.
Assertion is False, Reason is true.

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(1)

${Na}_{2} {Cr}_{2} O_{7}$ is hygroscopic and that is why, it is not used as a primary standard in volumetric analysis.

Q 6 :

What will be the n-factor of the reactant in the following reaction?

$M n {(N O_{3})}_{2} \overset{Δ}{\to} M n O_{2} + N O$

(4)

n-factor = 4

Topic Question Set

Q 1 :

In which of the following reaction, the underlined substance has been reduced?

Q 2 :

The correct group of halide ions which can be oxidized by oxygen in acidic medium is _______

Q 3 :

Identify disproportionation reaction

Q 5 :

Assertion: $N a_{2} C r_{2} O_{7}$ cannot be used as a primary standard in titrations.

Reason: $N a_{2} C r_{2} O_{7}$ is hygroscopic in nature.

Q 6 :

What will be the n-factor of the reactant in the following reaction?

$M n {(N O_{3})}_{2} \overset{Δ}{\to} M n O_{2} + N O$

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	Column-I		Column-II
(A)	Very dilute solution of HCl	(P)	$O_{2}$ evolved at anode
(B)	Very dilute solution of NaCl	(Q)	$H_{2}$ evolved at cathode
(C)	Concentrated solution of NaCl	(R)	${Cl}_{2}$ evolved at anode
(D)	Aqueous ${AgNO}_{3}$	(S)	Ag deposition at cathode

Topic Question Set

Q 1 : In which of the following reaction, the underlined substance has been reduced?

Q 2 : The correct group of halide ions which can be oxidized by oxygen in acidic medium is _______

Q 3 : Identify disproportionation reaction

Q 5 : Assertion: Na2Cr2O7 cannot be used as a primary standard in titrations. Reason: Na2Cr2O7 is hygroscopic in nature.

Q 6 : What will be the n-factor of the reactant in the following reaction? Mn(NO3)2→ΔMnO2+NO

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Q 1 :

In which of the following reaction, the underlined substance has been reduced?

Q 2 :

The correct group of halide ions which can be oxidized by oxygen in acidic medium is _______

Q 3 :

Identify disproportionation reaction

Q 5 :

Assertion: $N a_{2} C r_{2} O_{7}$ cannot be used as a primary standard in titrations.

Reason: $N a_{2} C r_{2} O_{7}$ is hygroscopic in nature.

Q 6 :

What will be the n-factor of the reactant in the following reaction?

$M n {(N O_{3})}_{2} \overset{Δ}{\to} M n O_{2} + N O$