Question

1. A sample of hydrochloric acid (HCI), which is an acid, with a mass of 0.7302 g is dissolved in water and used to standardize a solution of barium hydroxide. An endpoint is reached when 47.81 mL of barium hydroxide has been added. Determine the molarity (in mol/L) of the barium hydroxide solution. Report your answer to four significant figures. Submit Answer Tries 0/13 2. The standardized barium hydroxide solution is then used to titrate 13.86 mL of a solution of phenylammonium chloride (C6H5NH3CI). An endpoint is reached when 14.49 mL of barium hydroxide has been added. Determine the molarity (in mol/L) of the phenylammonium chloride solution. Report your answer to four significant figures. Submit Answer Tries o/13

Answer 1

Q1. molarity of barium hydroxide = 0.2094

Q2. molarity of phenylammonium chloride = 0.4379

Explanation

The balanced chemical reaction between HCl and Ba(OH)₂ is :

2 HCl (aq) + Ba(OH)₂ (aq) $\rightarrow$ BaCl₂ (aq) + 2 H₂O (l)

mass HCl = 0.7302 g

moles HCl = (mass HCl) / (molar mass HCl)

moles HCl = (0.7302 g) / (36.46 g/mol)

moles HCl = 0.02003 mol

moles Ba(OH)₂ = (1/2) * moles HCl

moles Ba(OH)₂ = (0.5) * (0.02003 mol)

moles Ba(OH)₂ = 0.01001 mol

molarity Ba(OH)₂ = (moles Ba(OH)₂) / (volume Ba(OH)₂ in Liter)

molarity Ba(OH)₂ = (0.01001 mol) / (47.81 x 10^-3 L)

molarity Ba(OH)₂ = 0.2094 M