Crayola Washable Markers Lab Report

The purpose of this experiment was to discover if Crayola Washable Markers are really nontoxic, or even as safe as the dyes used in food. To answer this question, we used paper chromatography to identify the dyes in blue, orange, and green Skittles Sweets and Sours candy and Crayola Washable Markers. In this paper chromatography experiment, the mixture to be separated was spotted 1.5 centimeters from the bottom of chromatography paper, which was then dipped in the solvent, a 0.1 percent salt solution. The solvent then moved up the filter paper via capillary action and carried the mixture's pigments with it (Rosen and Gothard, 2010). Each pigment has a unique retention factor or Rf, a ratio between how far a pigment travels to the distance …show more content…
By using paper chromatography, the dyes in blue, orange, and green Skittles Sweet and Sour Candy and Crayola Washable Markers will be separated and observed to determine the Rf value and identify the dyes used in Skittles Sweets and Sours candy and Crayola Washable Markers. Our hypothesis is that the dyes used in Crayola Washable Markers are different from the dyes used in Skittles Sweets and Sours candy. Chromatography is a group of techniques used to separate the components of a mixture by passing a mobile phase over a stationary phase (Rosen and Gothard, 2010). In our experiment, we will be using capillary action chromatography and more specifically paper chromatography. In paper chromatography, the mixture to be separated is spotted on filter paper, the stationary phase, which is then dipped in the solvent, the mobile phase (Rosen and Gothard, 2010). The solvent then moves up the filter paper via capillary action and carries the mixture's pigments with it (Rosen and Gothard, 2010). Capillary action occurs when adhesive forces, the attraction between particles of the same type, outweigh cohesive forces, attraction between two different particles (Ellis, n.d.). How far a mixture's pigments move up the filter paper depends on each pigment's solubility with the mobile phase (Science Buddies, 2014). More soluble pigments react more with the solvent than the filter paper, and get carried by the solvent further up the paper. Less soluble pigments react more with the filter paper than the solvent and travel a shorter distance. This gives each pigment a unique retention factor, a ratio between how far a pigment travels to the distance the mobile phase travels from a starting point. Retention factors are calculated using the formula Rf= distance traveled by sample component/ distance traveled by solvent (Science Buddies, 2014). In our experiment, the stationary