Question

a student has two samples of nacl, each one from a different source. assume that the only potential contaminant in each sample is kcl. the student runs an experiment to determine the percent by mass of chlorine in each sample. from the results of this experiment alone, which of the following questions is most likely to be answered? a which sample has the higher purity? b which sample has the higher density? c what is the source of the contaminants present in each of the samples? d which sample came from a salt mine, and which sample came from the ocean?

Explanation:

1. For option A: Pure NaCl has a fixed percent by mass of Cl. If a sample has KCl (which has a lower percent of Cl than NaCl, since K is heavier than Na), a lower Cl percent means more KCl (contaminant) and lower purity. So comparing Cl percent can show purity.
2. For option B: Density depends on factors like crystal structure, packing, not just Cl percent. The experiment measures Cl mass percent, not density - related data.
3. For option C: The experiment only looks at Cl percent, not the source of KCl (contaminant). It can't identify the source.
4. For option D: The experiment gives no info about the source (mine or ocean) of the NaCl samples, only about Cl percent.

Answer:

A. Which sample has the higher purity?