Answer to Question #291819 in Chemistry for Roro

Question

how would you solve “Suppose you have 150 mL of a 17.5% NH4OH solution (m/V). How many mL

of this solution would be needed to get 21.0g of NH4OH?”

Answer 1

Solution:

m/V = (Mass of solute in grams / Volume of solution in mL) × 100%

Hence,

17.5% = (Mass of NH₄OH / 150 mL) × 100%

0.175 = Mass of NH₄OH / 150 mL

Mass of NH₄OH = 26.25 grams

150 mL of this solution would be needed to get 26.25 grams of NH₄OH

X mL of this solution would be needed to get 21.00 grams of NH₄OH

Thus,

X mL = (21.00 g × 150 mL) / (26.25 g) = 120 mL

Answer: 120 mL of this solution would be needed.