A lotion vehicle contains 15% v/v of glycerin. How much glycerin in grams should be used in preparing 5 gallons of the lotion?

Answer 1

15% v/v means that there will be 15 mls of glycerin in every 100 mls of lotion.

How many mls are there in 5 gallons? The conversion would be something like this ...

1 gallon =~3785 mls

5 gallons x 3785 mls = 18,925 mls

18,925 mls x 15 ml glycerin/100 mls = 2839 mls of glycerin

Density of glycerin = 1.26 g/ml

2839 mls x 1.26 g/ml = 3577 g glycerin