Test and analysis: According to the information given in the title, Xiaoling poured a certain proportion of calcium carbonate powder and salt into a small beaker, then added a proper amount of glycerin (humectant), sweetener and essence, and made toothpaste after stirring evenly, from which it can be inferred that toothpaste belongs to a mixture; Carbon dioxide gas can react with limewater to produce calcium carbonate, and the chemical equation of the reaction is CO 2+Ca (OH) 2 = CaCO 3 ↓+H2O.
Comments: This topic belongs to information topic. It is not difficult for students to learn to extract effective information from the topic and analyze it.