A concentrated aqueous ammonia solution has a density of 0.90 g/mL and is 28.0% by mass ammonia. Determine the molar concentration of this solution.

Question

Quizplus · Accepted Answer

To find the molar concentration, first calculate the mass of ammonia in 1 L of solution: 0.90 g/mL x 1000 mL = 900 g of solution. 28% of this is ammonia, so 0.28 x 900 g = 252 g of NH3. The molar mass of NH3 is 17.03 g/mol, so 252 g / 17.03 g/mol = 14.8 mol, which is approximately 15 M.

A Concentrated Aqueous Ammonia Solution Has a Density of 0