Question

assuming 80 mg of vitamin C present in 29.57 ml of the orange juice, how many millileters of 0.0102 M KIO3 would be required to reach the stoichiometric point? i dont want just an answer, i want to know how to do it too. thanks!

Answer 1

Given data

Mass of vitamin C = 80 mg

                          = 0.080 g

Molarity of KIO3 = 0.0102 M

First we have to calculate the moles of vitamin C

Then balanced equation has to written

From the balanced equation and moles of vitamin C we can calculate volume of KIO3 required to reach stoichiometric point.

Moles of vitamin C = mass/molar mass

                           = 0.080 g / 176.12 g/mol

                           = 0.00045 mol

Balanced equation between KIO3 and vitamin C can be written as

3 C₆H₈O₆ + KIO₃ (aq) ---> 3 C₆H₆O₆ + KI (aq) + 3 H₂O(l)

From the above equation three moles of vitamin C reacts with 1 mole of KIO3

Moles of KIO3 required to react with 0.00045 moles of vitamin C

                                         = (0.00045 mol Vitamin C)*1mol KIO3/3 mole vitamin C

                                         = 0.00015 mol

Volume of KIO3 required = moles of KIO3 / molarity of KIO3

                                    = 0.00015 mol / 0.0102 mol/L

                                    = 0.0147 L

                                    = 14.7 mL     ( since 1 L = 1000 mL )

Hence the answer is 14.7 mL