Tag: Chemical indicators

The iodine-starch test, first discovered in 1814, is one of the most classic and visually striking chemical experiments in analytical chemistry. This test relies on a specific indicator to produce its famous color change, providing a precise signal for the presence of iodine in a solution.

According to food science, every food item is a combination of macromolecules, which form the building blocks of life. Learning how to identify which macromolecules are present in a food is a fundamental skill in biology and chemistry, relying on specific chemical indicators that change color when they react with a particular substance.

Compounds containing two or more peptide bonds, a key characteristic of proteins, give a purple color when treated with dilute copper sulfate in an alkaline solution. This principle is the basis for the Biuret test, which uses an indicator solution to detect proteins, polypeptides, and other compounds containing peptide bonds.