weight of the unknown sample = 1.013 g
sample was dissolved in 25.0 ml water and taken for analysis
it take 17.7 ml of 0.00480 M iodine
moles of iodine required = 8.5*10^-5 M
so the sample contains 8.5*10^-5 M of ascorbic acid
weight of ascorbic acid = 176.12*8.5*10^-5 = 0.015 g
percent of ascorbic acid = 1.48%
4. 1.013 g of an unknown solid mixture contains some ascorbic acid. It is dissolved in...
16 7-2 Titration Calculations Ascorbic acid (vitamin C) reacts with according to the equation Starch is used as an indicator in the reaction. The end point is marked by the appearance of a deep blue starch-iodine complex when the first fraction of a drop of unreacted remains in the solution. TI (a) Stundurdization: If 29.41 mL of iodine solution is required to react with 0.197 0 g of pure ascorbic acid, what is the molarity of the iodine solution?! (b)...
Calculate the weight percent of ascorbic acid in a tablet of Vitamin C from the following data: A 100 mg sample of a crushed Vitamin C tablet was dissolved in 40 mL of H2SO4 and 20 mL of water. Two grams of KI and 35 mL of 0.0107 M KIO3 solution was added, and the mixture titrated to a starch endpoint. The titration required 12 mL of 0.0790 M thiosulfate solution.
Ascorbic acid (vitamin C, MM 176.124 g/mol)) can be determined using an iodometric back titration. A vitamin C tablet was dissolved in 60 mL of 0.3 M H2S04. To the dissolved tablet, 2 g of KI and 50.00 mL of 0.0105 M KIO3 were added, resulting in the formation of a dark orange solution indicating the presence of 13-. The resulting solution was titrated with 0.0685 M S2032- until the starch indicator turned purple. If the end point was observed...
A sample of 0.2140 g of an unknown monoprotic weak acid was dissolved in 25.0 mL of water and titrated with 0.0950 M NaOH. The acid required 15.50 mL of NaOH to reach the equivalence point. What is the molar mass of the unknown acid?
You have a 1.153 g sample of an unknown solid acid, HA, dissolved in enough water to make 20.00 mL of solution. HA reacts with KOH(aq) according to the following balanced chemical equation: HA(aq) + KOH (aq) --> KA (aq) + H20 (l) If 13.40 mL of 0.600 M KOH is required to titrate the unknown acid to the equivalence point, what is the concentration of the unknown acid? What is the molar mass of HA?
3) Use the mole ratios contained in both equation 3 and
equation 4 to calculate the
volume (in mL) of 0.0100 M potassium iodate solution needed to
completely oxidize all
of the ascorbic acid contained in 20.00 mL of 0.0200 M
ascorbic acid solution.
concentration of the titrant can be used along with the mole ratios from the reaction equations to determine the amount of ascorbic acid in the solution Chemical Reactions involved with the redox titration: Equation 1 shows...
A tablet containing some Vit C (ascorbic acid) was dissolved in water then titrated with 24.88 ml of 0.1085 M NaOH. What is the w/w% of Vit C in the tablet if the tablet weighed 0.6672 g? (use Vit C = 176.0 g/mol) NaOH + Vit C rightarrow sodium ascorbate + H_2O
A sample of 0.2140 g of an unknown monoprotic acid was dissolved in 25.0 mL of water and titrated with 0.0950 M NaOH. The titration required 30.0 mL of base to reach the equivalence point, at which point the pH was 8.68. a) What is the molecular weight of the acid? b) What is the pKa of the acid?
(A) A 14.5 g sample of an aqueous solution of hydrobromic acid contains an unknown amount of the acid. If 26.8 mL of 0.557 M barium hydroxide are required to neutralize the hydrobromic acid, what is the percent by mass of hydrobromic acid in the mixture? (B) A 13.7 g sample of an aqueous solution of nitric acid contains an unknown amount of the acid. If 19.8 mL of 0.682 M potassium hydroxide are required to neutralize the nitric acid,...
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(0.0034 / 0.035) times 100 Percent ionization = 9.7% A solid mixture contains both MgCl2 and NaCl. When 0.5000 g of this mixture is dissolved in enough water to form 1.000 L of solution, the osmotic pressure at 25.0 Degree C is observed to be 0.3990 atm. What is the mass percent of MgCl2 in the solid? (Assume ideal behavior for the solution and that both ionic compounds dissociate completely in the water.)