Problem: A 2.800x10-2 M 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.Calculate the mole fraction of salt in this solution.

FREE Expert Solution

Mole Fraction (X) relates the moles of solute and solvent within a solution:

mole fraction (X)=mole of solutemole of solution



Step 1: Calculate the mole of solute 


 Recall molarity (M):    assuming we have 1 L of solution

molarity = moles soluteLsolution2.800 × 10-2  = mole NaCl1 Lmoles NaCl = 0.0280 mol


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Problem Details

A 2.800x10-2 M 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.


Calculate the mole fraction of salt in this solution.

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