Unsure on how to calculate NaCl concentration Shown below is

Unsure on how to calculate NaCl concentration????

Shown below is a dilution protocol of a 5M stock solution of NaCI. The lines above indicate how much volume you are transferring to the volume of water Indicated in the tube. For each tube state the dilution factor and concentration of NaCl.

Solution

Answer:

Dilution is defined as reduction of the concentration of a solution by adding diluent such as water. And the Dilution factor is the ratio of the initial volume (of solute/solution) to the final volume of any solution.

In the given case, the 5M NaCl is to be diluted using water as diluent.

Thus, dilution factor for tube A = 5/(5+5) = 1:2

The dilution factor for tube B = 2.5/(2.5+7.5) = 2.5/10 = 1:4

The dilution factor for tube C = 3/ (3+3) = 3/6 = 1:2

The final concentration of a solution can be calculate using the following formula:

N₁V₁ = N₂V₂

where as, N₁ is the initial concentration of the solution

N₂ is the final concentration of the solution

V₁ is the initial volume of the solution

V₂ is the final volume of the solution

For tube A, N1 = 5M; V1= 5 ml; V2 = 10 ml; N2 = ?

N2 = N1V1/V2

= (5M x 5 ml) / 10 ml

= 25/10 = 2.5 M

For tube B, N1 = 2.5M; V1= 2.5 ml; V2 = 10 ml; N2 = ?

N2 = N1V1/V2

= (2.5M x 2.5 ml) / 10 ml

= 6.25/10 = 0.625 M

For tube C, N1 = 0.625M; V1= 3 ml; V2 = 6 ml; N2 = ?

N2 = N1V1/V2

= (0.625M x 3 ml) / 6 ml =1.875 / 6

= 0.3125 M