Which scan result shows that there may be two or more matches for the unknown substance?

Which scan result shows that there may be two or more matches for the unknown substance?

• A. Multiple positive match
• B. Single positive match
• C. Mixture
• D. Similar match

Answer: (D)

When a spectrum is compared to a library, you’re looking for how clearly one candidate stands out. A single positive match means there’s a strong, unique identification. If several candidates seem plausible, the system may flag a similar match to indicate ambiguity. This tells you there may be two or more substances with spectra that closely resemble the unknown, and none stands out as the definitive identity. A mixture would suggest the sample itself contains more than one compound, changing the spectral pattern, rather than simply creating ambiguity among library entries. So the presence of a similar match points to multiple plausible identities for the unknown.

When a spectrum is compared to a library, you’re looking for how clearly one candidate stands out. A single positive match means there’s a strong, unique identification. If several candidates seem plausible, the system may flag a similar match to indicate ambiguity. This tells you there may be two or more substances with spectra that closely resemble the unknown, and none stands out as the definitive identity. A mixture would suggest the sample itself contains more than one compound, changing the spectral pattern, rather than simply creating ambiguity among library entries. So the presence of a similar match points to multiple plausible identities for the unknown.