1. Which of the following options are correct for the reaction

$2 {[Au (CN)_{2}]}^{-} (aq) + Zn (s) \to 2 Au (s) + {[Zn (CN)_{4}]}^{2 -} (aq)$

A. Redox reaction

B. Displacement reaction

C. Decomposition reaction

D. Combination reaction

Choose the correct answer from the options given below: ⇒ (JEE Main 2023 (Online) 6th April Morning Shift)

A. A and B only

B. C and D only

C. A only

D. A and D only

Correct answer is option (A)

$2 {[\overset{+ 1}{Au} (CN)_{2}]}^{-} + \overset{0}{Z} n (s) ⟶ 2 \overset{0}{Au} + {[\overset{+ 2}{Zn} (CN)_{4}]}^{- 2}$

$Zn$ displaced ${Au}^{+}$

Reduction and Oxidation both are taking place.

2. The incorrect statement is : ⇒ (JEE Main 2021 (Online) 26th August Morning Shift )

A. Cl₂ is more reactive than ClF.

B. F₂ is more reactive than ClF.

C. On hydrolysis ClF forms HOCl and HF.

D. F₂ is a stronger oxidizing agent than Cl₂ in aqueous solution.

Correct answer is option (A)

(i) Reactivity order :

F₂ > ClF (inter halogen) > Cl₂

(ii) ClF + H₂O $\to$ HOCl + HF

(iii) Oxidizing power is aqueous solution

F₂ > Cl₂ > Br₂ > I₂

3. The redox reaction among the following is : ⇒ (JEE Main 2020 (Online) 7th January Evening Slot)

A. reaction of H₂SO₄ with NaOH.

B. formation of ozone form atmosphere oxygen in the presence of sunlight.

C. combination of dinitrogen with dioxygen at 2000 K

D. reaction of [Co(H₂O)₆]Cl₃ With AgNO₃

Correct answer is option (C)

N₂ + O₂ $\to$ 2NO

during the reaction, oxidation of nitrogen take place from 0 to 2 and reduction of oxygen take place from 0 to –2. It means this reaction is redox reaction.

3O₂ $\to$ 2O₃ (Non - redox reaction)

2NaOH + H₂SO₄ $\to$ Na₂SO₄ + 2H₂O (neutralization reaction)

[Co(H₂O)₆]Cl₃ + 3AgNO₃ $\to$ 3AgCl $↓$ + [Co(H₂O)₆](NO₃)₃

Reaction of [CO(H₂O)₆]Cl₃ with AgNO₃ is not redox reaction. It is a precipitation reaction.

4. Which of the following reactions is an example of a redox reaction? ⇒ (JEE Main 2017 (Offline))

A. $X e F_{6}$ + H₂O $\to$ $X e O F_{4}$ + 2HF

B. $X e F_{6}$ + 2H₂O $\to$ $X e O_{2} F_{2}$ + 4HF

C. $X e F_{4}$ + O₂F₂ $\to$ $X e F_{6}$ + O₂

D. $X e F_{2}$ + PF₅ $\to$ ${[X e F]}^{+} P F_{6}^{-}$

Correct answer is option (C)

JEE Main 2017 (Offline) Chemistry - Redox Reactions Question 41 English Explanation

5. Copper becomes green when exposed to moist air for a long period. This is due to: ⇒ (JEE 12 April 2014 (Online) )

A. the formation of a layer of cupric hydroxide on the surface of copper

B. the formation of basic copper sulphate layer on the surface of the metal

C. the formation of a layer of cupric oxide on the surface of copper

D. the formation of a layer of basic carbonate of copper on the surface of copper

Correct answer is option (D)

The formation of layer of a basic carbonate of copper on the surface of copper.
When a copper vessel is exposed to moist air for a long time it develops a green layer on it surface. Copper corrodes by oxidation in which it reacts with oxygen in the air to form copper oxide.
Copper oxide then combines with carbon dioxide to make copper carbonate, which gives it a green colour. This process is called corrosion of copper.
The green material is a mixture of copper hydroxide (Cu(OH)₂) and copper carbonate (CuCO₃). The following is the reaction :
2Cu_(s) + H₂O_(g) + CO₂ + O₂ ⇒ Cu(OH)₂ + CuCO₃_(s)
Copper (II) carbonate is a blue-green compound.

6. Which of the following is a redox reaction ? ⇒ (AIEEE 2002)

A. NaCl + KNO₃ $\to$ NaNO₃ + KCl

B. CaC₂O₄ + 2HCl $\to$ CaCl₂ + H₂C₂O₄

C. Mg(OH)₂ + 2NH₄Cl $\to$ MgCl₂ + 2NH₄OH

D. Zn + 2AgCN $\to$ 2Ag+ Zn(CN)₂

Correct answer is option (D)

AIEEE 2002 Chemistry - Redox Reactions Question 43 English Explanation

The oxidation state shows a change only in (d)

⇒Redox

Topic 1 : Oxidation and Reduction Reaction