10g of nacl were added to 10ml of water. the resulting solution was diluted to be a final volume of 250ml. Given the density of the solution is 0.9864g/ml. Calculate the molality of the solution.
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To calculate the molality of the solution, we need to know the amount of solute (NaCl) in moles and the amount of solvent (water) in kilograms.
First, let's find the moles of NaCl. The molar mass of NaCl is 58.44 g/mol.
Moles of NaCl = Mass of NaCl / Molar mass of NaCl
= 10 g / 58.44 g/mol
= 0.171 mol
Next, let's find the mass of water. We have 10 ml of water, and we know the density of the solution is 0.9864 g/ml.
Mass of water = Volume of water x Density
= 10 ml x 0.9864 g/ml
= 9.864 g
To convert the mass of water to kilograms:
Mass of water = 9.864 g / 1000
= 0.009864 kg
Finally, we can calculate the molality using the formula:
Molality (m) = Moles of solute / Mass of solvent (in kg)
= 0.171 mol / 0.009864 kg
= 17.34 mol/kg
Therefore, the molality of the solution is 17.34 mol/kg.