Question

The formula for a buffer solution contains 1.24% w/v of boric acid. How many milli-liters of a 5% w/v boric acid solution should be used to obtain the boric acid needed in preparing 1 liter of the buffer solution?

Answer 1

Answer: 248mL

Step-by-step explanation:

Given:

Concentration of buffer solution Cs = 1.24%w/v of boric acid

Concentration of boric acid solution Cb = 5 % w/v boric acid

For 1 liter of buffer solution, the weight of boric acid needed is:

mb = 1 × 1.24 = 1.24 unit weight

mb = Cb × Vb .....1

Cb = concentration of boric acid solution.

Vb = volume of boric acid solution needed.

mb = weight of boric acid needed.

From equation 1.

Vb = mb/Cb

Vb = 1.24/5

Vb = 0.248L

Vb = 248mL