Question

How many mLs of sterile water need to be added to a 3g vial to make 500mg/mL
solution?

Answer 1

Explanation:

500 mg = 500 × 1 g / 1000 = 1/2 g = 0.5 g

so, the original target ratio is

0.5 g / 1 ml

the ratio has to be maintained when adding x ml of the sterile water to the 3 g.

3 g / x ml = 0.5 g / 1 ml

3 g / 0.5 g = x ml / 1 ml

3/0.5 = x

x = 6

only with x = 6 do we keep the target ratio.

so, we need to add 6 ml to the 3 g vial to make it a 500 mg/ml solution.