Lab 9 - Experiment 9-1 (Acids and Bases) Objective: To...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Objective : To demonstrate acids and bases. Results, Explanations, Conclusions : For this experiment we put red cabbage in a pan with some water and boil it for a few minutes. The water then turned purple with the cabbage and we put it into a jar. We then placed a small amount of this solution in several test-tubes. Then we added the soda pop, lemon juice, vinegar, soapy water, baking soda, water, and bleach to each tube. Before adding the solid substances to the test-tubes we dissolved them in water. We then observed and recorded the color change in each tube. Then we also tested all substances by dipping pieces of pH paper into them. After we referred to a pH scale to determine which colors represented acids and bases. Three of the results obtained were from soda pop, soapy water and bleach. From soda pop it was discovered that it had a pH number of 3.0 and the cabbage juice color was pinkish. From this it can be concluded that soda pop is an acid. The soapy water was found to have a pH number of 6.0 and the cabbage juice color was purple-pink. It can be concluded from this that soapy water is an acid. Also bleach was found to have a pH number of 12.0 and the cabbage juice color was green. From this it can be concluded that bleach is a base. Both indicators show a change for both acids and bases because with the cabbage juice the pinker signals an acidic substance. In the cabbage juice color the more blue-green color shows that the substance is a base. The pH number lower than 7 signals the more acidic it is and the pH number higher than 7 equals a base. When the pH number is 7 it signals that the substance is neutral. The acidic qualities of a substance are determined by more hydrogen ions, which are H positive. The basic qualities of a substance are determined by more hydroxide ions, which are OH negative. Teaching Applications : -“Candy Catastrophe”: For this experiment bring in a variety of candy to the class. Make sure that within the selection you have Sprees and Warheads. Explain to the children that Sprees have a pH number of 3.0 and Warheads have a pH number if 1.6, which means they are acidic. Warheads are very acidic and discuss with them that because of this, candy is bad for kid’s teeth. -“Secret Message”: In this experiment get lemon juice, pieces of blank paper and cabbage juice. Have the children write on the pieces of paper with lemon juice. The message will not appear and can be seen as secret. Then spray the paper with cabbage juice and this will make the message appear and able to be seen. This is a fun way to understand the principles of acids and bases. Diagram
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 6

Lab 9 - Experiment 9-1 (Acids and Bases) Objective: To...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online