Answer to Question #165752 in Chemistry for Phyroe

Question

Express in formality the concentration of 28.4 per cent in NH3 by weight having a density of 0.808 grams per ml

Answer 1

Let's assume that we have 1 L of NH₃ solution of 28.4%.

If its density is 0.808 grams per ml, the mass of 1 L is 808 g or 0.808 kg.

% = 100 x m_(solute) / (m(_solute) + m_(solvent))

m_(solute)NH₃ = (808 x 28.4)/100 = 229.5 g

C_M = n/V

n = m/M

M (NH₃) = 17.03 g/mol

n (NH₃) = 229.5 / 17.03 = 13.48 mol

C_M (NH₃) = 13.48 / 1 =13.48 M