Question

Iodine reacts with aqueous thiosulfate ion in neutral solution according to the balanced equation 12(aq) + 25,03 -(aq) S4062(aq) + 27- (aq) How many grams of 12 are present in a solution if 35.20 mL of 0.150 M Na2S2O, solution is needed to titrate the la solution?

Answer 1

Answer: 0.67 g

Step-by-step explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

`Molarity=\frac{moles}{\text {Volume in L}}`

`moles of [tex]Na_2S_2O_3=Molarity* {\text {Volume in L}}=0.150* 0.0352=5.28* 10^(-3)moles`

`I_2(aq)+2S_2O_3^(2-)(aq) S_4O_6^(2-)(aq)+2I^-(aq)`

According to stoichiometry:

2 moles of
`2S_2O_3^(2-)(aq)` require 1 mole of
`I_2`

Thus
`5.28* 10^(-3)moles` require=
`(1)/(2)* 5.28*10^(-3)=2.64* 10^(-3)` moles of
`I_2`

Mass of
`I_2=moles* {\text {molar mass}}=2.64* 10^(-3)* 254=0.67g`

Thus 0.67 g of iodine are present in the solution.