In: Chemistry
5- Ascorbic acid (molecular weight = 176.12) is too acidic to administer by the parenteral route. The acidity of ascorbic acid is partially neutralized by adding a basic compound, usually sodium carbonate or sodium bicarbonate. Thus, the injectable product contains sodium ascorbate, ascorbic acid and the neutralizing agent.
a. What is the pH of an injectable solution containing only ascorbic acid in the concentration of 55 g per liter of solution (Ka1 = 5 x 10-5 and Ka2 = 1.6 x 10-12).
b. What is the molar ratio of sodium ascorbate to ascorbic acid and the percentage required to prepare an injectable solution with a pH of 5.77?