A solution of I2 in aqueous KI on reaction with an aqueous solution of Na2S2O3 gets decolourised. The reaction taking place here is

Question

A solution of I2 in aqueous KI on reaction with an aqueous solution of Na2S2O3 gets decolourised. The reaction taking place here is (A) Na2S2O3+H2O+I2 arrow Na2S2O4+2HI (B) 2Na2S2O3+I2 arrow Na2S4O6+2NaI (C) Na2S2O3+2H2O+2I2 arrow Na2S2O5+4HI (D) Na2S2O3+2H2O+2I2 arrow Na2S4O8+4HI

Tardigrade Admin · Accepted Answer

On running sodium thiosulphate solution into an iodine solution (in KI solution), the reddish-brown colour is gradually discharged through yellow to colourless.

I_{2} + 2 e^{-} \to 2 I^{-}

2 N a_{2} S_{2} O_{3} \to N a_{2} S_{4} O_{6} + 2 N a^{+} + 2 e^{-}

2 N a_{2} S_{2} O_{3} + I_{2} \to N a_{2} S_{4} O_{6} + 2 N a^{+} I^{-}

Q. A solution of $I_{2}$ in aqueous KI on reaction with an aqueous solution of $N a_{2} S_{2} O_{3}$ gets decolourised. The reaction taking place here is

$N a_{2} S_{2} O_{3} + H_{2} O + I_{2} \to N a_{2} S_{2} O_{4} + 2 H I$

$2 N a_{2} S_{2} O_{3} + I_{2} \to N a_{2} S_{4} O_{6} + 2 N a I$

$N a_{2} S_{2} O_{3} + 2 H_{2} O + 2 I_{2} \to N a_{2} S_{2} O_{5} + 4 H I$

$N a_{2} S_{2} O_{3} + 2 H_{2} O + 2 I_{2} \to N a_{2} S_{4} O_{8} + 4 H I$

Q. A solution of I2​ in aqueous KI on reaction with an aqueous solution of Na2​S2​O3​ gets decolourised. The reaction taking place here is

Na2​S2​O3​+H2​O+I2​→Na2​S2​O4​+2HI

2Na2​S2​O3​+I2​→Na2​S4​O6​+2NaI

Na2​S2​O3​+2H2​O+2I2​→Na2​S2​O5​+4HI

Na2​S2​O3​+2H2​O+2I2​→Na2​S4​O8​+4HI

On running sodium thiosulphate solution into an iodine solution (in KI solution), the reddish-brown colour is gradually discharged through yellow to colourless. I2​+2e−→2I− 2Na2​S2​O3​→Na2​S4​O6​+2Na++2e− 2Na2​S2​O3​+I2​→Na2​S4​O6​+2Na+I−

Q. A solution of $I_{2}$ in aqueous KI on reaction with an aqueous solution of $N a_{2} S_{2} O_{3}$ gets decolourised. The reaction taking place here is

$N a_{2} S_{2} O_{3} + H_{2} O + I_{2} \to N a_{2} S_{2} O_{4} + 2 H I$

$2 N a_{2} S_{2} O_{3} + I_{2} \to N a_{2} S_{4} O_{6} + 2 N a I$

$N a_{2} S_{2} O_{3} + 2 H_{2} O + 2 I_{2} \to N a_{2} S_{2} O_{5} + 4 H I$

$N a_{2} S_{2} O_{3} + 2 H_{2} O + 2 I_{2} \to N a_{2} S_{4} O_{8} + 4 H I$