Introduction: Aim: The aim of this experiment is to determine the chemical nature of an unknown solution by examining how it reacts with different indicators and comparing the results obtained from these reactions to those of the same indicators with several different, known, solutions. General Background: There are many different macromolecules present in nature, the most predominant molecules found in living organisms. In analytical chemistry, indicators are chemicals (reagents) that help identify the composition of an unknown material. In solution analysis, indicators are used to predict the presence of certain organic or inorganic compounds such as sugars, proteins, starches, lipids, or vitamins. There are two types of testing, qualitative …show more content…
However this is simply a qualitative indication, and further tests would have to be conducted in order to determine the quantitative nature of the solution. The qualitative tests do however set a guideline for what quantitative tests to conduct next as the nature of the solution would be known. Due to the unexpected results obtained for the iodine test, one may say that this is due to an error in performing the experiment, a proposed error is that the tube had not been properly cleaned and thus may have contained chemicals which would lower the pH of the solution accounting for the clear colour obtained. Conclusions: Based on the dark purple colour obtained in the iodine test as well as the two negative results obtained for the , Biuret and copper sulphate and Sudan III test I would conclude that the unknown solution is either a starch solution or a chemical substance that has similar chemical to those of starch. Works Cited food chemistry experiments. (2012, January 02). Retrieved October 05, 2014, from science company: http://www.sciencecompany.com/food-chemistry-experiments-W151.aspx#3 Campus, H. C.-Y. (2013, august 12). Retrieved October 2014, 5, from hccfl: