Lime water: Full syllabus notes

Full syllabus notes, lecture and questions for NCERT Solutions for Class 7 Science Chapter 2 Exploring Substances: Acidic, Basic and Neutral - Class 7 - Plus excerises question with solution to help you revise complete syllabus for Science (Curiosity) Class 7 - New NCERT - Best notes, free PDF download Activity 2.1: Let us explore Collect samples of lemon juice, soap solution, amla juice, tamarind water , vinegar, baking soda solution, lime water , tap water , washing powder solution, sugar solution, and salt solution. Take a strip of blue litmus paper and cut it into small pieces. Spread these pieces on a clean and dry white tile. Using a dropper, put one drop of each of the samples, one-by-one, on these litmus paper pieces, as shown in Fig. 2.2a. In glass tumbler B ( lime water ), blowing air creates bubbles, and the lime water turns milky (cloudy). After some time, a white substance (calcium carbonate) settles at the bottom (page 4). Ans.When air is blown into lime water , carbon dioxide from the air reacts with calcium hydroxide in the lime water . This reaction produces calcium carbonate, which makes the lime water turn milky or cloudy.