Enter your answer in the provided box. an industrial chemist studying bleaching and sterilizing prepares a hypochlorite buffer using 0.450 m hclo and 0.450 m naclo. (ka for hclo = 2.9 × 10−8) find the ph of 1.00 l of the solution after 0.040 mol of naoh has been added.

Explanation:

1. pH of original buffer

(a) Calculate pKₐ

(b) Calculate the pH

We can use the Henderson-Hasselbalch equation to get the pH.

2. pH after adding strong base

(a) Find new composition of the buffer

The base reacts with the HA and forms A⁻

                 HA     +     OH⁻    ⟶     A⁻ + H₂O

I/mmol:    450            40              450

C/mmol:    -40           -40                 40

E/mmol:    410               0              490

(b) Find the new pH  

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%