Three black ink pens (Pen X, Pen Y, and Pen Z) found at a potential crime scene are tested to see if their ink matches. The color of the inks is identical to the naked eye, but they may have different chemical compositions.
A forensic chemist compares the dyes in the three different inks using paper chromatography. The resulting chromatogram is shown below:
Calculate the RfR_{\text{f}}Rf value of the magenta spot. Give your answer to 2 significant figures.
Which two pens would you expect to contain identical ink? Explain your answer using the chromatogram data.
Commercial inks are complex mixtures where active ingredients, binders, and solvents are combined in exact, predetermined proportions to serve a specific, designed purpose. What general name is given to a mixture designed as a useful product in this way?
Stainless steel (a mixture of iron, carbon, and chromium) is also a mixture of elements combined in precise proportions to achieve desired physical properties. What type of substance is stainless steel? Select one option:
- Allotrope
- Alloy
- Fullerene
- Isotope
- Polymer
In a separate experiment, a student attempts to separate the components of a different solvent-resistant marker ink. However, they find that both the dye components remain on the baseline and fail to separate. What modification should the student make to their experimental setup to successfully achieve separation?