Chapter 4. Percent Concentrations (1 of 20) Sample Questions

1. How many grams of chemical are required to make 120 mL of a 20% w/w solution with a specific gravity 1.15?
  1. A. 15 g
  2. B. 37 g
  3. C. 27 g
  4. D. 10 g
Ans: C
Tips:
Wt of solution= sp. gravity * wt of same volume of water
= 1.15 *120 = 138 grams
so
20 g------>100 g solution
x g………>138 g of solution
X = 138 × 200/100 = 27 g