Answer to Question #86139 in General Chemistry for taha

Question

To determine the concentration of a solution of nitric acid, a 150.0-mL sample is placed in a flask and titrated with a 0.1175 M solution of barium hydroxide. A volume of 31.46 mL is required to reach the phenolphthalein endpoint. Calculate the concentration of nitric acid in the original sample.


_______ M.

Answer 1

x mol 0.0037 mol

2HNO₃ + Ba(OH)₂ = Ba(NO₃)₂ + 2H₂O

2 mol 1 mol

n(Ba(OH)₂) = C(Ba(OH)₂) * V(Ba(OH)₂) = 0.1175 M * 0.03146 L = 0.0037 mol.

n(HNO₃) = x = 0.0037 *2 / 1 mol = 0.00185 mol.

C(HNO₃) = n(HNO₃) / V(HNO₃) = 0.00185 mol / 0.15 L = 0.0123 M.