Determine molarity of the following solutions: a. 0.36 moles BaCl2 dissolved in enough water to make 0.90 L solutions.

Answer 1

Molarity = moles of solute/liter of solution. So, 0.36 mol/0.90 L = 0.40 moles/L or 0.40 Molar

molality = moles of solute/kg of solvent. To do this calculation, we need to make an assumption. Namely, the water has a density of 1.00 g/mL. Hence, we would have 0.90 kg. So, m = 0.36 mol/0.90 kg = 0.40 mole/kg or 0.40 molal. Thus, the M & m are the same.