Jean Lab

In this lab, we asked the question what concentration of bleach is best to fade the color out of new denim material in 10 minutes without visible damage to the fabric. We found that a higher concentration of 100% took out the most amount of color on the jeans but damaged the fabric the most, because when we ranked the color removal and the fabric damage on a scale of 10, the average for the color removal was a 7 and a 4 for a the fabric damage. But with the smallest concentration of 0%, we found that there was no damage to the jeans and no color was taken out, as the average for both the color removal and the fabric damage was 0. However with the 25% concentration of bleach, the highest amount of color was taken out without any visible damage to the fabric, as the average for the color removal was a 4 and there was no fabric damage. These results could be supported by knowledge about the properties of bleach saying that bleach breaks down pigments and gets the color of the clothes as close as possible to white because 100% of bleach broke down many of the pigments and removed most of the color of the jeans, and the lower concentrations broke down fewer of the pigments and took out only a little of the color.

While our hypothesis was supported by our data, there could have been a few errors that affected our experiment. While doing the experiment, the times that we left the bleached jeans out before dousing it in water were not controlled and varied between each concentration. Also, the water we used as our negative control became contaminated, because when measuring the water in the graduated cylinder, the water got contaminated with bleach because before pouring the water in the graduated cylinder, we had poured the 100% concentration, the 50% concentration, the 25% concentration, and the 12.5% concentration of bleach. In the future, to not repeat the mistakes made that could have had a slight effect on our experiment, almost invalidating it, we could have one person designated to keep track of the timings making sure everything is controlled. Also, regarding the error of contaminating the water, we should have done the experiment starting with 0% and ending with the 100% concentration rather than the other way around like what we did during the experiment.

This purpose of the lab was to familiarize ourselves and demonstrate our knowledge of the scientific method through an experiment. Through this lab, we learned where we were at in the scientific method, meaning we learned what we were good at and what we weren’t good at. We learned that we were able to follow instructions but need to pay attention more on making the experiment controlled. Based on my experience from this lab, I know the scientific method and am able to use it properly in an experiment.