Question

measured concentration of vitamin C in fruit juice. ( mol/L)

Type of juice Ppple Volume of container: 200mL Volume per serving: aob mL Servings per container: % RDA of vitamin C per serving: 1007 Calculated concentration of vitamin C based on packaging: RDA for vitamin C: 90 mg O.45 mg/mL 2.55X 10o ,mol/L Calculated molar concentration of vitamin C based on packaging: (assume molar mass is equal to that of ascorbic acid, 176.12 g/mol) Titration Data: 0.00Sm Concentration of lodine Standard (on bottle) 00x t0m Trial 1 Trial 2 Trial 3 డింmU 13.30ML 13.2aml 13.80 ML Initial Buret Reading: Final Buret Reading: 12.30ML L-IOm Volume of Iodine Solution: 1LeomL tISX10o 5 SSXI x0mol Moles of Vitamin C in solution: S mal S.SSXO S&x\0mo Moles of lodine Added: Measured concentration of vitamin C in fruit juice (mol/L): Average concentration of vitamin C in fruit juice (mol/L): % Error relative to label: 0.45mn 176 12gImul 257

Answer 1

4) Measured concentration of vitamin C

= moles×1000/volume (ml)

For trail 1 : molar concentration = 6.15×10^-5×1000/200

= 3.075×10^-4 mol/L

For trail 2 : molar concentration = 5.55×10^-5×1000/200

= 2.775×10^-4 mol/L

For trail 3 : molar concentration = 5.8×10^-5×1000/200

= 2.9×10^-4 mol/L

5) Average concentration = (3.075+2.775+2.9)×10^-4/3

= 8.75×10^-4/3 = 2.917×10^-4

6) Calculated molar concentration = 0.45/176.12

= 2.55×10^-3 mol/L

% error = (2.55×10^-3-2.917×10^-4)×100/2.55×10^-3 = 88.75%