Question

17.27 ml of Na2S2O3 (aq) was required to titrate 25.00 ml of 0.0104 M KIO3 (aq) solution. What is the concentration of the Na2S2O3(aq) solution?

Options:
A) 0.002 M
B) 0.005 M
C) 0.010 M
D) 0.020 M

Answer 1

To find the concentration of the Na2S2O3(aq) solution, use the balanced equation and a proportion to solve for x. The concentration of the Na2S2O3(aq) solution is 0.0146 M.

Step-by-step explanation:

To find the concentration of the Na2S2O3(aq) solution, we can use the equation:

KIO3(aq) + 2Na2S2O3(aq) → I2(aq) + Na2SO4(aq) + NaIO3(aq)

From the balanced equation, we can see that 2 moles of Na2S2O3(aq) react with 1 mole of KIO3(aq). Therefore, we can set up the following proportion:

(0.0104 M KIO3)(25.00 mL) = (x M Na2S2O3)(17.27 mL)

Solving for x, we find that the concentration of the Na2S2O3(aq) solution is 0.0146 M.