1. A sample of hydrochloric acid is standardized using sodium
bicarbonate.
a. Write the balanced chemical equation for the reaction of
hydrochloric acid with sodium bicarbonate, NaHCO3
b. Calculate the molar concentration of the hydrochloric acid
if 35.18 mL of hydrochloric acid was required to neutralize 0.450 g
of sodium bicarbonate to a phenolphthalein end point.
c. Calculate the mass percent concentration of hydrochloric
acid using the molar concentration calculated in part b and
assuming the density of the solution is 1.01 g/mL
2. Malonic acid, H2C3H2O4, is a diprotic acid, so 2 moles of
hydroxide ions are required per mole of malonic acid for complete
neutralization.
a. Write the balanced chemical equation for the reaction of
the malonic acid with potassium hydroxide.
b. Calculate the molar concentration of the malonic acid if
38.17 mL of 0.315 M potassium hydroxide was required to neutralize
25.0 mL of molanic acid to a phenolphthalein end point.
c. Calculate the mass percent concentration of molanic acid
using molar concentration calculated in part b and assuming the
density of the solution is 1.01 g/mL
3. Citric acid is a tripotic acid, so 3 moles of hydroxide
ions are required per mole of citric acid for complete
neutralization.
a. Write the balanced chemical equation for the reaction of
citric acid with sodium hydroxide. (Note that citrate ion is
actually a polyatomic ion with carbon, hydrogen, and oxygen atoms
and an overall charge of -3. For now, please express citrate ion as
Cit^3-)
b. If 36.10 mL of 0.223 M NaOH is used to neutralize a 0.515 g
sample of citric acid, what is the molar mass of the acid?