The video shows a person using a chemical to test the pH level of a liquid. The person is holding a bottle of chemical and pouring it into a test tube that is part of a pH meter. The pH meter has multiple test tubes, each with a different color, indicating different pH levels. The person is pouring the chemical into the test tube that is red, and as the chemical is added, the color of the liquid in the test tube changes from red to orange. The pH meter has a scale on the side that shows the pH level for each color. The person is carefully pouring the chemical to ensure the correct amount is added to the test tube.