A buffer solution has 0.625 M HCN and 0.575 M CN⁻. If 0.030 mol of HCl is added to 400. mL of the buffer solution, what is the pH after the addition? The pKa of hydrocyanic acid is 9.23.

A 1.0 L buffer solution contains 0.100 mol HC2H3O2 and 0.100 mol NaC2H3O2. The value of Ka for HC2H3O2 is 1.8 × 10⁻⁵. Calculate the pH of the solution upon the addition of 0.015 mol of NaOH to the original buffer.

A 1.0 L buffer solution contains 0.100 mol HC2H3O2 and 0.100 mol NaC2H3O2. The value of Ka for HC2H3O2 is 1.8×10⁻⁵. Calculate the pH of the solution upon the addition of 10.0 mL of 1.00 M HCl to the original buffer using the Henderson-Hasselbalch equation.

A 270.0 mL buffer solution initially contains 3.0×10⁻² M of HCHO₂ and 3.0×10⁻² M of NaCHO₂. To adjust the buffer pH to 4.10, should you add NaOH or HCl to the buffer mixture?

A buffer consists of 0.120 M HNO2 and 0.150 M NaNO2 at 25 °C. The pKa of HNO2 is 3.40. What is the pH of the buffer?

Using the Henderson-Hasselbalch equation, what is the pH of a buffer solution that is 0.250 M in HCN and 0.170 M in KCN, given that the pKa of HCN is 9.31?

Consider a buffer solution that is 0.50 M in NH3 and 0.20 M in NH4Cl. For ammonia, pKb = 4.75. Calculate the pH of 1.0 L of the solution upon addition of 30.0 mL of 1.0 M HCl to the original buffer solution.

Consider a buffer solution that is 0.50 M in NH3 and 0.20 M in NH4Cl. For ammonia, pKb = 4.75. Calculate the pH of 1.0 L of the solution upon addition of 0.010 mol of solid NaOH to the original buffer solution.

Consider a buffer solution that is 0.50 M in NH3 and 0.20 M in NH4Cl. For ammonia, pKb = 4.75. Calculate the pH of 1.0 L of the solution upon the addition of 30.0 mL of 1.0 M HCl to the original buffer solution.