Question

Dye stock solutions are 400X and 40X stock. How much of each is needed to make a 2X solution in 5mls?

Answer 1

For this, we will sue formula

C1V1 =C2V2

For 400x

C1 = Concentration of stock = 400

V1 = Volume of stock = X

C2 = Concentration of solution = 2

V2= Volume of solution = 5

Now

C1V1 = C2V2

400*X = 2*5

x= 10/400 = 0.025 mL

So 0.025 mL of 400X is needed to make 5mL of 2x.

For 40x

C1 = Concentration of stock = 40

V1 = Volume of stock = X

C2 = Concentration of solution = 2

V2= Volume of solution = 5

Now

C1V1 = C2V2

40*X = 2*5

x= 10/40 = 0.25 mL

So 0.25 mL of 40X is needed to make 5mL of 2x.