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1. From the volume of titrant added, calculate the moles of vitamin C for each t

ID: 583595 • Letter: 1

Question

1. From the volume of titrant added, calculate the moles of vitamin C for each titration. Show a sample calculation for trial 1, and then just state the final results for the calculation of trials 2 and 3. Use 5 digits in all intermediate values and report the final value to the appropriate number of significant figures. 0.6612 g vitamin C KIO3- 0.002012 MM KI- 0.3 M HCl= 1.0 M Trial 1 Trial 3 40.62 14.00 26.62 Trial 2 26.49 Final buret reading37..21 Initial buret readin Volume of KIO3 10.00 27.21 26.49

Explanation / Answer

Write the balanced equation of reaction vitamin C and KIO3

KIO3 + 3 C6H8O6 = 3 C6H6O6 + 3 H2O + KI

Concentration of KIO3 solution = 0.002012M (given)

For 1st trial

Volume of KIO3 added = 27.23 ml

Covert volume in L by dividing with 1000

27.23 ml/1000 = 0.02723 L

Calculate the moles of KIO3 by using formula n = c v

n = 0.002012M x (0.02723) L = 5.4789 x 10^-5 moles

Reaction stoichiometry show1:3 molar relationships between KIO3 and ascorbic acid.

So, moles of ascorbic acid = 3 moles of KIO3

                                              = 3 x 5.4789 x 10^-5 moles

                                              = 1.6437 x 10^-4 moles

                                           = 1.64 x 10^-4 moles

For 2nd trial

Volume of KIO3 added = 26.49 ml

Calculate the moles of KIO3 by using formula n = c v

n = 0.002012M x (0.02649) L = 5.3298 x 10^-5 moles

Reaction stoichiometry show1:3 molar relationships between KIO3 and ascorbic acid.

So, moles of ascorbic acid = 3 moles of KIO3

                                              = 3 x 5.3298 x 10^-5 moles

                                              =1.5989 x 10^-4 moles

                                           = 1.6 x 10^-4 moles

For 3rd trial

Volume of KIO3 added = 26.62 ml

Calculate the moles of KIO3 by using formula n = c v

n = 0.002012M x (0.02662) L = 5.3559 x 10^-5 moles

Reaction stoichiometry show1:3 molar relationships between KIO3 and ascorbic acid.

So, moles of ascorbic acid = 3 moles of KIO3

                                              = 3 x 5.3559 x 10^-5 moles

                                              =1.6068 x 10^-4 moles

                                           = 1.61 x 10^-4 moles