Question

Use the Henderson–Hasselbalch equation to calculate the pH of each solution:

Part A) a solution that is 0.115 M in HClO and 0.160 M in KClO

Part B) a solution that contains 1.29% C2H5NH2 by mass and 1.27% C2H5NH3Br by mass

Part C)  a solution that is 14.0 g of HC2H3O2 and 13.5 g of NaC2H3O2 in 150.0 mL of solution

Answer 1

In all the three parts of the question you asked to find the molarity of the conjugate base or the conjugate acid and of the acid or base respectively.

After you are found the concentrations you just get into the henderson hasselbalch equation. For the percent by mass calculation, you need to convert the given percent by mass to molarity.

To do that you have to divide the percent by mass with the molar mass to get the number of moles. And the volume is given. Molarity is the number of moles per unit volume. Provided the volume is in litre. 1000 ml of solution is equals to 1 litre.