Question

A chemist needs to determine the concentration of a solution of nitric acid, HNO3. She puts 875 mLof the acid in a flask along with a few drops of indicator. She then slowly adds 0.200 MBa(OH)2 to the flask until the solution turns pink, indicating the equivalence point of the titration. She notes that 145 mL of Ba(OH)2 was needed to reach the equivalence point.

Solution map

In this titration, the concentration of base is known and can be used to calculate the unknown acid concentration:

concentration of base ⟶ moles of base ⟶ moles of acid ⟶ concentration of acid

Part A

How many moles of Ba(OH)2 are present in 145 mL of 0.200 M Ba(OH)2?

Express your answer with the appropriate units.

Answer 1

Solution une g nitric acid = 875 ml = 0.875L Concertation of Ba (orth = 0.200 M Volume of Baotle = 145ml = 0.145 L nog moles y Ba(OH) = in 145 ml of 0.2009 0.200 moles 0.145 X 1(Concertation & = 0.029 moles og and t are the equal equivalence point, the role to the mola of bace moles of acids me Concentration of concertection of Pease & Volume of Base acid (HINO) = - lolan g Acid 0.029 - 0.0331 M .895