you used a pencil to mark the chromatography paper since the carbon in the "lead" pencil does not dissolve in the solute. why does carbon not dissolve? what type of pen (ink) will also not produce a chromatogram when water is used as the solovent? explain using principles based of the polarity of particles
Carbon doesn't dissolve in water because C is not polar. India ink is essentially C (I think lamp black) and will not dissolve in water.
Carbon does not dissolve in water because it is a nonpolar substance, meaning it lacks an electrical charge. Water is a polar molecule, with a positive charge on one end (hydrogen) and a negative charge on the other end (oxygen). Since like dissolves like, polar substances dissolve in polar solvents, and nonpolar substances dissolve in nonpolar solvents.
When water is used as the solvent in chromatography, only substances that are polar or have polar functional groups will dissolve and separate on the chromatography paper. This is because the water molecules attract polar substances more strongly, allowing them to travel up the paper.
If we consider the ink in a pen, there are different types of ink that can be used. Some inks are water-based and will produce a chromatogram when water is used as a solvent. These inks contain polar substances that can dissociate or dissolve in water.
However, some pens use an ink that is not water-based. These inks are often oil-based or use nonpolar solvents. Since water is a polar solvent, it will not dissolve or separate the components of these nonpolar inks. Therefore, when water is used as the solvent, these nonpolar inks will not produce a chromatogram because their particles lack the polarity required to be attracted and separated by the water molecules on the chromatography paper.