Answer:
The correct option is;
A. Which sample has the higher purity
Explanation:
The information given relate to the presence of two samples of NaCl, from different sources
The only potential contaminant in each of the sources = KCl
The content of the sample = NaCl
The molar mass of NaCl = 58.44 g/mol
The molar mass of KCl = 74.5513 g/mol
Let the number of moles of KCl in the sample = X
For a given mass of NaCl, KCl mixture, we have;
The molar mass of potassium = 39.0983 g/mol
The molar mass of chlorine = 35.453 g/mol
The molar mass of sodium ≈ 23 g/mol
Therefore;
Each mole of KCl, will yield 35.453 g/mol per 74.5513 g/mol of KCl
While each mole of NaCl will yield 35.453 g/mol per 58.44 g/mol of NaCl
Therefore, the pure sodium chloride sample will yield more chlorine per unit mass of sample.
As such if the two samples have the same mass, the sample with the contaminant of KCl will yield less mass of chlorine per unit mass of the sample, from which the student will be able to tell the purity of the solution.
The sample with the higher purity will yield a higher mass chlorine per unit mass of the sample.
