Question

Choose the correct statement(s) among the following.

Answer 1

QUESTION:

Choose the correct statement among the following

• A) SnCl₂.2H₂O is a reducing agent.

• B) SnO₂ reacts with KOH to form K₂[Sn(OH)₆].

• C) A solution of PbCl₂ in HCl contains Pb⁺² and Cl⁻ ions.

• D) The reaction of Pb₃O₄ with hot dilute nitric acid to give PbO₂ is a redox reaction.

ANSWER:

The correct statements are

• A) SnCl₂.2H₂O is a reducing agent.

• B) SnO₂ reacts with KOH to form K₂[Sn(OH)₆].

• D) The reaction of Pb₃O₄ with hot dilute nitric acid to give PbO₂ is a redox reaction.

GIVEN STATEMENTS:

• A) SnCl₂.2H₂O is a reducing agent.

• B) SnO₂ reacts with KOH to form K₂[Sn(OH)₆].

• C) A solution of PbCl₂ in HCl contains Pb⁺² and Cl⁻ ions.

• D) The reaction of Pb₃O₄ with hot dilute nitric acid to give PbO₂ is a redox reaction.

TO FIND:

• The correct statements.

EXPLANATION:

A) SnCl₂.2H₂O is a reducing agent.

• A) SnCl₂.2HO is a reducing agent as well an anti-oxidant and also a food colour.

• Therefore statement A) is correct.

B) SnO₂ reacts with KOH to form K₂[Sn(OH)₆].

$\sf SnO_2 + KOH+ H_2O\ \longrightarrow \ \red{K_2[\ Sn(OH)_6\ ]}$

• K₂[Sn(OH)₆] is formed.

• Therefore statement B) is correct.

C) A solution of PbCl₂ in HCl contains Pb⁺² and Cl⁻ ions.

$\sf PbCl_2 + HCl \ \longrightarrow\ \orange{ H[\ PbCl_3\ ]}$

• Here H[ PbCl₃ ] complex is formed.

• H[ PbCl₃ ] on dissociation gives H⁺ and [ PbCl₃ ]⁻ ions.

• So it cannot further dissocciate into contain Pb⁺² and Cl⁻ ions.

• Therefore statement C) is incorrect.

D) The reaction of Pb₃O₄ with hot dilute nitric acid to give PbO₂ is a redox reaction.

$\sf Pb_3O_4 + 4HNO_3 \ \longrightarrow\ 2Pb(NO_3)_2 + \blue{PbO_2} + H_2O$

• Here PbO₂ is formed.

• Oxidation state of Pb in Pb₃O₄ is +8/3.

• Let the oxidation state of Pb in Pb(NO₃)₂ be x.

• x - 2 = 0 => x = 2 [ Oxidation state of (NO₃)₂ = 2(-1) = -2 ]

• So oxidation state of Pb in Pb(NO₃)₂ is +2.

• Let the oxidation state of Pb in PbO₂ is +4.

• As oxidation state of Pb changes before and after the reaction it is a redox reaction.

• Also it is an example of disproportionation reaction which is a type of redox reaction.

• Therefore statement D) is correct.

Answer 2

Choose the correct statement (s) among the following.

(A) SnCl₂.2H₂O is a reducing agent.

(B) SnO₂ reacts with KOH to form K₂[Sn(OH)6]

(C) A solution of PbCl₂ in HCl contains Pb²⁺ and Cl¯ ions.

(D) The reaction of Pb₃O₄ with hot dilute nitric acid to give PbO₂ is a redox reaction.

solution : option (A) is correct choice, SnCl₂.2H₂O acts as reducing agent where Sn²⁺ tends to convert into Sn⁴⁺ ion.

reaction of SnO₂ with KOH (potassium hydroxide), gives K₂[Sn(OH)6] complex .

SnO₂ + 2KOH + 2H₂O → K₂[Sn(OH)6] , so option (B) is also correct choice.

PbCl₂ in the presence of HCl, converts into [PbCl₄]²¯, so option (C) is incorrect.

Pb₃O₄ + 4HNO₃ → PbO₂ (↓) + 2Pb(NO₃)₂ + 2H₂O, it is precipitate reaction so the reaction of Pb₃O₄ with hot dilute nitric acid to give PbO₂ is not a redox reaction. so option (D) is incorrect.

Therefore options (A) and (C) are correct choices.