Answer to Question #300102 in Chemistry for Erika01

Question

The density of concentrated ammonia, which is 28.0% w/w NH₃, is 0.899 g/mL. What volume of this reagent should be diluted to 1.0 × 10³ mL to make a solution that is 0.036 M in NH₃? 

Answer 1

n₁ = n₂

C_M = n / V

n = C_M x V

n = m / M

M (NH₃) = 17 g/mol

n (NH₃) = 0.036 x 1 = 0.036 mol

m (NH₃) = 0.036 x 17 = 0.612 g

m (NH₃)_28% = (0.612 x 100) / 28 = 2.186 g

Density = m / V

V = m / density

V (NH₃)_28% = 2.186 / 0.899 = 2.432 mL