If a chromatogram has more than one peak it indicates the sample is a:

• A. A pure substance
• B. A mixture
• C. An alloy
• D. A solution

Answer: (B)

In chromatography, each distinct substance in a sample produces its own peak as it comes out of the column. If you see more than one peak, it means there are several different components present that have been separated. A pure substance would typically give just a single peak, corresponding to that one component. An alloy isn’t something described by a chromatogram in this sense, since it’s a solid metal composition rather than separated substances. A solution is a homogeneous mixture, and while it could contain more than one solute that might show multiple peaks, the clearest takeaway from multiple peaks in a chromatogram is that the sample is a mixture.