Answer:
Molality of the NaCl solution is 2.084 mol/kg.
Explanation:
Molarity of the solution is the moles of compound in 1 Liter solutions.
[tex]Molarity=\frac{\text{Mass of compound}}{\text{Molar mas of compound}\times Volume (L)}[/tex]
Molarity of the NaCl solution = 2 M
This means that in 1 liter solution there are 2 moles of NaCl.
Volume of the NaCl solution, V = 1 L = 1000 mL
Density of the solution = d = 1.0768 g/mL
Mass of solution= m
[tex]Mass=Density\times volume [/tex]
[tex]m=d\times V=1.0768 g/mL\times 1000 mL=1076.8 g[/tex]
Mass of 2 moles of NaCl =58.5 g/mol × 2 mol = 117 g
Mass of solution = Mass of solvent + mass of solute
Mass of solvent = Mass of solution - mass of solute
= 1076.8 g - 117 g = 959.8 g
Mass of solvent = 959.8 g = 0.9598 kg
[tex]Molality=\frac{\text{Mass of compound}}{\text{molar mass of compound}\times mass of solvent(kg)}[/tex]
Molality of the NaCl solution:
[tex]=\frac{117 g}{58.5 g/mol\times 0.9598 kg}=2.084 mol/kg[/tex]
