Question

Q.1.
Which of the following is a redox reaction as well as displacement reaction?
A. 2HgCl2+SnCl2--->Hg2Cl2+SnCl4
B. ZnO+C--->Zn+CO
C. 2Al+6HCl--->2AlCl3+3H2
D. H2S+Cl2--->2HCl+S

Q.2.
Which of the following statement is incorrect ?
A. All elements are homogeneous
B. Compounds always contains who or more different elements
C. A mixture is not always heterogeneous
D. Air is an heterogeneous mixture

Q.3.
Copper objects loose their lusture or shine after sometime. This surface of these objects acquire a green coating of basic copper carbonate CuCO3Cu(OH)2 which is also called rust of copper. This is due to ?

Q.4.
Rusting of iron is a chemical reaction. The reaction can be termed as ?

Q.5.
In which of the following reaction'Zn' undergo oxidation ?

Q.6.
The formula for rust is

Q.7.
In the reaction PbO+C--->Pb+cO
1. Pbo is oxidized
2. C acts on as an oxidising agent
3. C acts as a reducing agent
4. This reaction does not represents redox reaction

Q.8.
Ferric oxide reacts with aluminium metal upon heating to form aluminium oxide and iron. In this reaction, Fe2O3 acts...

Q.9.
During the reaction of Zn with H2SO4
1. Zn loses electrons
2. Zn gains electrons
3. Zn gets reduced
4. Both 2 & 3

Q.10.
Following reaction represents a redox reaction in this process:
2Na+Cl---->2NaCl
1. Na get oxidized
2. Cl2 get oxidized
3. Cl is oxidizing agent
4. Both 1 & 3


Help me fast please

Answer 1

Answer:

Explanation:

Q.1 B

Q.2 D

Q.3 due to corrosion

Q.4 decomposition reaction

Q.7 3

Q.9 1

Q.10 4

Answer 2

1. (Option C)

$2Al +6HCl$  →  $2AlCl_{3}+3H_{2}$ is a redox reaction as well as displacement reaction.

This is because $Cl$ is getting displaced and at the same time $HCl$ is getting reduced.

2. (Option D)

Air is a homogeneous mixture. This is because we cannot separate the components of air using simple methods.

3. The green coating on copper is due to oxidation of copper.

When metals are left in atmosphere, they react with oxygen present in the air and forms oxide which makes the outer covering.

4. Rusting of iron can be termed as oxidation reaction.

This is because iron gets oxidized in air when kept for too long. This oxide of iron has been given a special name 'rust' and the process is termed as rusting of iron.

5. The reaction in which oxidation of zinc takes place can be,

$Zn+FeSO_{4}$  →  $ZnSO_{4}+Fe$

This is because the oxidation state of Zn increases whereas that of Fe decreases.

6. The formula for rust is,

$2Fe_{2}O_{3}.H_{2O}$

7. (Option 3)

In the given reaction C is a reducing agent because it itself is getting oxidized.

This is a redox reaction where lead is getting reduced and carbon is getting oxidized.

8. In the reaction between ferric oxide and aluminum metal, ferric oxide acts as an oxidizing agent.

The reaction is,

$Fe_{2}O_{3}+2Al$  →  $Al_{2}O_{3}+2Fe$

9. (Option 3)

The reaction between zinc and sulphuric acid is given as,

$Zn+H_{2}SO_{4}$  →  $ZnSO_{4}+H_{2}$

• In this reaction, Zinc acts as an oxidizing agent and gets reduced.

• The oxidation state of zinc reduces as it gains electron.

10. (Option 4)

The redox reaction between sodium and chlorine is given by,

$2Na+Cl^{-}$  →  $2NaCl$

In the above reaction,

• Na gets oxidized and Cl is oxidizing agent.
• This is because the initial oxidation state of Na which is 0, gets increased to +1.