Problem: A 2.950×10−2M solution of NaCl in water is at 20.0°C. The sample was created by dissolving a sample of NaCl in water and then bringing the volume up to 1.000 L. It was determined that the volume of water needed to do this was 999.2 mL . The density of water at 20.0°C is 0.9982 g/mL.Part ACalculate the molality of the salt solution. Express your answer to four significant figures and include the appropriate units.Part BCalculate the mole fraction of salt in this solution. Express the mole fraction to four significant figures.Part CCalculate the concentration of the salt solution in percent by mass. Express your answer to four significant figures and include the appropriate units.Part DCalculate the concentration of the salt solution in parts per million. Express your answer as an integer to four significant figures and include the appropriate units.

FREE Expert Solution

Recall equations for a) molalityb) mole fraction, c) percent by mass and d) ppm


Molality(m)=moles solutekg solvent   


mole fraction (X)=mole of solutemole of solution


mass percent = mass componenttotal mass×100


ppm=mass of solutemass of solution×106


solute → NaCl


solvent → H2O


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Problem Details

A 2.950×10−2M solution of NaCl in water is at 20.0°C. The sample was created by dissolving a sample of NaCl in water and then bringing the volume up to 1.000 L. It was determined that the volume of water needed to do this was 999.2 mL . The density of water at 20.0°C is 0.9982 g/mL.

Part A

Calculate the molality of the salt solution. Express your answer to four significant figures and include the appropriate units.

Part B

Calculate the mole fraction of salt in this solution. Express the mole fraction to four significant figures.

Part C

Calculate the concentration of the salt solution in percent by mass. Express your answer to four significant figures and include the appropriate units.

Part D

Calculate the concentration of the salt solution in parts per million. Express your answer as an integer to four significant figures and include the appropriate units.


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