Ascorbic acid (vitamin C) is a diprotic acid having the formula H2C6H6O6. A sample of a vitamin supplement was analyzed by titrating a 0.2894 g sample dissolved in water with 0.0215 M NaOH. A volume of 10.83 mL of the base was required to completely neutralize the ascorbic acid. What was the percentage by mass of ascorbic acid in the sample?

Question

______________% ascorbic acid

Answer 1

1. Write the equation and balance it.
2. moles NaOH = M x L = ?
3. Using the coefficients in the balanced equation, convert moles NaOH to moles ascorbic acid.
4. moles asc acid x molar mass asc acid = grams ascorbic acid.
5. %ascorbic acid = (grams ascorbic acid/mass sample)*100 = ?

Answer 2

Suppose 15.0 mL of 0.315 M NH4Cl is combined with 10.0 mL of 0.430 M (NH4)3PO4. Assume the volumes are additive, and no chemical reaction takes place. What is the total cocentration of ammonium ions in this mixture?

Answer 3

9.33 * 10^22 ions NH4

Answer 4

4M