200X buffer is given in class.How much of stock sol and how much distilled water is used to make?
a)50 ml of a 1X buffer solution?
b)100 ml of a 20X buffer solution?
c)10 ml of a 400X solution
the only possible anwer if you are diluting with water is starting with a concentration greater than what you end with. Ans c.
To determine the amount of stock solution and distilled water needed to make different volumes of buffer solution, we can use the formula:
V1C1 = V2C2
Where:
V1 = Volume of stock solution
C1 = Concentration of stock solution
V2 = Final volume of buffer solution
C2 = Desired concentration of buffer solution
Let's calculate the amounts of stock solution and distilled water needed for each scenario:
a) 50 ml of a 1X buffer solution:
C1 = 200X (concentration of stock solution)
C2 = 1X (desired concentration of buffer solution)
V2 = 50 ml (final volume of buffer solution)
Using the formula:
V1C1 = V2C2
V1 * 200X = 50 ml * 1X
V1 = (50 ml * 1X) / 200X
V1 = 0.25 ml
To make 50 ml of a 1X buffer solution, you would need to mix 0.25 ml of the 200X stock solution with 49.75 ml of distilled water.
b) 100 ml of a 20X buffer solution:
C1 = 200X (concentration of stock solution)
C2 = 20X (desired concentration of buffer solution)
V2 = 100 ml (final volume of buffer solution)
Using the formula:
V1C1 = V2C2
V1 * 200X = 100 ml * 20X
V1 = (100 ml * 20X) / 200X
V1 = 10 ml
To make 100 ml of a 20X buffer solution, you would need to mix 10 ml of the 200X stock solution with 90 ml of distilled water.
c) 10 ml of a 400X buffer solution:
C1 = 200X (concentration of stock solution)
C2 = 400X (desired concentration of buffer solution)
V2 = 10 ml (final volume of buffer solution)
Using the formula:
V1C1 = V2C2
V1 * 200X = 10 ml * 400X
V1 = (10 ml * 400X) / 200X
V1 = 20 ml
To make 10 ml of a 400X buffer solution, you would need to mix 20 ml of the 200X stock solution with 0 ml of distilled water (since the concentration is already at the desired level).