Redox Reaction

Q.

When the copper oxide is heated with hydrogen, copper metal and water are formed. What happens to the hydrogen in this reaction?

1. Oxidation
2. Both oxidation and reduction
3. Decomposition
4. Reduction

Q. The copper-plated 'Statue of Liberty' is greenish blue in colour rather than orange–red, this is because of __________ reaction.

1. sonority
2. oxidization
3. malleability
4. solubility

Q. Which of the following is true about redox reactions?

1. In a redox reaction, only oxidation reaction happens.
2. In a redox reaction, oxidation and reduction happen simultaneously.
3. In a redox reaction, only reduction reaction happens.
4. None of these.

Q.

Write the reaction between sulphur and iron filings.

Q.

Define :

(a) catalytic hydrogenation

(b) oxidation

(c) reduction

(d) redox reaction

Q.

Explain Redox reaction

Q.

Fill in the blanks.

(a) Hydrogen is ___ than air.

(b) Hydrogen is ___ soluble in water.

(c) Hydrogen burns with a ___ flame and ___ sound is heard.

(d) A Metal ___ hydrogen in the reactivity series gives hydrogen with ___

(e) Hydrogen reacts with metal oxides to form ___ and ___

(f) Oxidation is the removal of ___ or addition of ___

(g) In redox reactions oxidation and reduction occur ___

Q.

Cupric oxide will be converted to metallic copper when it is heated with hydrogen.

1. False

2. True

Q.

Write word equations for two chemical reactions with the help of materials given in the box. [Air, copper sulfate, iron, vinegar, iron oxide, carbon dioxide, iron sulfate, copper, lime water, water]

Q. Which among the following statement(s) is(are) correct for the redox reaction given below?
${\text{Pb}}_3{\text{O}}_4+8\text{HCl}\stackrel{\text{Heat}}{\to }3{\text{PbCl}}_2+{\text{Cl}}_2+4{\text{H}}_2\text{O}$

1. $\text{HCl}$ is oxidised
2. $\text{HCl}$ is reduced
3. ${\text{Pb}}_3{\text{O}}_4$ is reduced
4. ${\text{Pb}}_3{\text{O}}_4$ is oxidised

Q.

Which of the following is/are reduction reaction?

1. Zn²⁺ + 2^e- → Zn

2. Fe²⁺ → Fe³⁺ + e^-

3. Hg²⁺ + 2^e- → Zn

4. MnO₄^2- → MnO₄^- + e^-

Q. H​​​​​​2​​​​S + Cl​​​​​2 ---> 2HCl + S

Prove that the given reaction is a redox reaction, stating reasons and define it.

Q. Copper oxide is heated with hydrogen to form copper metal & water. Identify the oxidising agent.

1. Water
2. Copper oxide
3. Hydrogen
4. Copper

Q. During photosynthesis plants give out .

1. oxygen
2. carbon dioxide
3. nitrogen

Q.

But why they react with all of them and what if they won't react

Q. is a phenomenon in which the fats and oils present in food get oxidized.

1. Corrosion
2. Rancidity
3. Rusting

Q. In redox reactions, oxidation and reduction take place simultaneously.

1. True
2. False
3. Either
4. Neither

Q. The reducing agent undergoes ________ of electrons.

1. loss
2. neither gain nor loss
3. both A and B
4. gain

Q.

Which of these is not a type of chemical reaction?

1. Oxidation

2. Decomposition

3. Displacement

4. Radiation

Q. Zinc oxide reacts with charcoal to form:

1. zinc and carbon dioxide
2. zinc and carbon monoxide
3. zinc and hydrogen
4. zinc and water

Q. 2Cu + O2 ->2CuO , it is oxidation reaction or redox reaction?

Q. Copper oxide is heated with hydrogen to form copper metal & water. Identify the oxidising agent.

1. Copper oxide
2. Copper
3. Hydrogen
4. Water

Q. Zinc oxide reacts with charcoal to form:

1. zinc and hydrogen
2. zinc and water
3. zinc and carbon dioxide
4. zinc and carbon monoxide