Question

Which of the following reactions involves oxidation-reduction
1) NaBr+HCl=NaCl+HBr 2)HBr+AgNO3=AgBr+HNO3 3)H2+Br2=2HBr 4)2NaOH+H2SO4=Na2SO4+2H2O Justify ur ans. On the basis of every equation?

Answer 1

Answer:(3)

Explanation:

Answer 2

Answer: The correct answer is Option 3.

Explanation:

Oxidation-reduction reaction or redox reaction is defined as the reaction in which oxidation and reduction reaction occur simultaneously.

Oxidation reaction is defined as the chemical reaction in which an atom looses its electrons. The oxidation number of the atom gets increased during this reaction.

$X\rightarrow X^{n+}+ne^-$

Reduction reaction is defined as the chemical reaction in which an atom gains electrons. The oxidation number of the atom gets reduced during this reaction.

$X^{n+}+ne^-\rightarrow X$

For the given options:

• Option 1:

The chemical equation follows:

$NaBr+HCl\rightarrow NaCl+HBr$

This is a type of double displacement reaction in which exchange of ions takes place.

• Option 2:

The chemical equation follows:

$HBr+AgNO_3\rightarrow NaNO_3+AgBr$

This is a type of double displacement reaction in which exchange of ions takes place.

• Option 3:

The chemical equation follows:

$H_2+Br_2\rightarrow 2HBr$

Oxidation half reaction:  $H_2\rightarrow 2H^++2e^-$

Reduction half reaction:  $Br_2+2e^-\rightarrow 2Br^-$

This is a type of redox reaction.

• Option 4:

The chemical equation follows:

$2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O$

This is a type of neutralization reaction in which an acid reacts with a base to produce salt and water.

Hence, the correct answer is Option 3.