A 245.0 mL sample of 0.15 M Ba(OH)₂ is added to 438 mL of 0.2 M HNO₃. What is the pH of the resulting solution?

Question

Quizplus · Accepted Answer

The reaction between Ba(OH)2 and HNO3 is a neutralization reaction where Ba(OH)2, a strong base, reacts with HNO3, a strong acid. The moles of Ba(OH)2 are 0.245 L * 0.15 M = 0.03675 moles, and the moles of HNO3 are 0.438 L * 0.2 M = 0.0876 moles. Since HNO3 is in excess (0.0876 - 0.03675*2 = 0.0141 moles remaining), the solution will be acidic. The concentration of excess HNO3 is 0.0141 moles / (0.245 L + 0.438 L) = 0.019 M. The pH is calculated using the formula pH = -log[H+], where [H+] is the concentration of the excess HNO3. Thus, pH ≈ 1.68, indicating an acidic solution.

A 2450 ML Sample of 0