Question

2. How do you determine the number of grams of an active ingredient in a solution based on the percent strength?

Answer 1

You need to know what kind of percent it is; i.e., % by mass(w/w), % w/v or % v/v.

If % w/v for example, that is mass [(solute/mL solution)]*100 = %
If it is a 5% w/v solution that is 5 g solute in 100 mL solution and you want to know grams in 50 mL, that is
(x/50)*100 = 5
(x/50)= 0.05
x = 50 x 0.05 = 2.5 g solute in that solution.

Answer 2

Calculate the normality of 2gCacl2 dissolved in 200ml water