How much of a 25mg/ml chloramphenicol stock solution do we need to make 400ml of growth media that has final 25ug/ml concentration of chloramphenicol?

Answer : The volume of chloramphenicol stock solution needed is, 0.4 mL

Explanation :

First we have to calculate the mass of chloramphenicol.

As, the mass of chloramphenicol in 1 mL of solution =

So, the mass of chloramphenicol in 400 mL of solution =

Thus, the mass of chloramphenicol is, 0.01 g

Now we have to calculate the volume of chloramphenicol stock solution needed.

Concentration of chloramphenicol =

As, of chloramphenicol needed 1 mL volume of chloramphenicol stock solution

So, of chloramphenicol needed volume of chloramphenicol stock solution

Thus, the volume of chloramphenicol stock solution needed is, 0.4 mL

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