Calculate the molality of a solution that contains 103 g naphthalene C10H8 dissolved in 3.45 mol carbon tetrachloride?

Answer 1

molality is mol solute per kg solvent. Using rounded integers for the molar masses gives:

mol C10H8 = 103/(10 x 12 + 8 x 1) = 103/128 = 0.805

kg CCl4 = 3.45 mol x 154 g/mol x 1 kg/1000 g = 0.5313 kg

m = 0.805/0.5313 = 1.52