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?

Question

asked Sep 3, 2021 103k views

1 Answer

CoreSOLO · Answer 1 · 2021-09-06T15:20:20+0000

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 =
$25\mu g=25* 10^(-6)g$

So, the mass of chloramphenicol in 400 mL of solution =
(400mL)/(1mL)* 25* 10^(-6)g=0.01g

Thus, the mass of chloramphenicol is, 0.01 g

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

Concentration of chloramphenicol =
25mg/mL=25* 10^(-3)g/mL

As,
25* 10^(-3)g of chloramphenicol needed 1 mL volume of chloramphenicol stock solution

So,
0.01g of chloramphenicol needed
(0.01g)/(25* 10^(-3)g)* 1mL=0.4mL volume of chloramphenicol stock solution

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