Question

You have a large bottle of 2% saline solution in the lab (2% NaCl, which is sodium chloride). You need 5 ml of 0.1% saline for an experiment. Do the calculation for the dilution you would need to make (i.e., calculate the volume of 2% saline and the volume of water you would need to combine).

Answer 1

volume of 2% saline (V₁) = 0.25ml

volume of water = 4.75ml

Step-by-step explanation:

The requirement in the question is to obtain 0.1% of NaCl from 2% NaCl, and the process is dilution. The general dilution equation is guven by:

C₁V₁ = C₂V₂

where:

C₁ = initial concentration = 2%

V₁ = initial volume = ?

C₂ = final concentration = 0.1%

V₂ = final volume = 5ml

C₁V₁ = C₂V₂

calculating for V₁

∴ V₁ = (C₂V₂) ÷ C₁

= (0.1% × 5) ÷ 2%

V₁ = 0.25ml

Now, let us calculate the volume of water needed:

V₁ + Volume of water = V₂ (volume of 0.1% NaCl)

0.25 + volume of water = 5

volume of water = 5 - 0.25

volume of water = 4.75ml