Class name Subject Book title Chapter number Content Created at
Class X Science Science 13 in forms which cannot be used again. The flow of energy between various components of the environment has been extensively studied and it has been ...
Class X Science Science 13 autotrophs. As it moves progressively through the various trophic levels it is no longer available to the previous level. Secondly,theenergyavailab...
Class X Science Science 13 to reduce our intake of Q U E S T I O N S 1. What are trophic levels? Give an example of a food chain and state the different trophic levels in it....
Class X Science Science 13 CFC production at 1986 levels. It is now mandatory for all the manufacturing companies to make CFC-free refrigerators throughout the world. Activit...
Class X Science Science 13 everything we eat? Enzymes are specific in their action, specific enzymes are needed for the break-down of a particular substance. That is why we w...
Class X Science Science 13 there a system in place to collect this waste? ■ Find out how the local body (panchayat, municipal corporation, resident welfare association) deals...
Class X Science Science 13 making these kulhads on a large scale would result in the loss of the fertile top-soil. Now disposable paper-cups are being used. What do you think...
Class X Science Science 2 CHAPTER 2 Acids, Bases and Salts ou have learnt in your previous classes that the sour and bitter Y tastesoffoodareduetoacidsandbases,respectively,...
Class X Science Science 2 T I O N 1. You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a ba...
Class X Science Science 2 drops of dilute NaOH solution on the other. 18 Science Reprint 2026-27 ■ Rinse both cloth strips with water and again check their odour. ■ Note you...
Class X Science Science 2 gas and forms a compound called a salt. Thus, the reaction of a metal with an acid can be summarised as – Acid + Metal → Salt + Hydrogen gas Canyou...
Class X Science Science 2 excess carbon dioxide the following reaction takes place: CaCO (3)+ H O(2)+ CO (g)2→Ca(HCO ) (aq) 3 2 (Soluble in water) Limestone,chalkandmarblear...
Class X Science Science 2 what do you infer about the acidic character of: (i) dry HCl gas Figure 2.4 Preparation of HCl gas (ii) HCl solution? Note to teachers: If the clim...
Class X Science Science 2 → H O(l) Let us see what is involved when water is mixed with an acid or a base. Activity 2.10 ■ Take 10 mL water in a beaker. ■ Add a few drops of...
Class X Science Science 2 to the acid? 5. How is the concentration of hydronium ions (H O ) affected when a ? solution of an acid is diluted? 3 6. How is the concentration o...
Class X Science Science 2 paper -imate substance pH value ■ Test the pH values of solutions given in 1 Saliva (before meal) Table 2.2. ■ Record your observations. 2 Saliva (...
Class XI Accountancy Financial Accounting-I 3 (viii) It affects Bank on the assets side on one side and liability on the other side. There is decrease in bank by ` 35,000 on the assets side and...
Class X Science Science 2 mouth after eating food. Using toothpastes, which are generally basic, for cleaning the teeth can neutralise the excess acid and prevent tooth deca...
Class X Science Science 2 H (aq) ions? If yes, then why are these basic? 4. Under what soil condition do you think a farmer would treat the soil of ?is fields with quick lim...
Class X Science Science 2 strong acid and weak base areacidicwithpHvaluelessthan7andthose of a strong base and weak acid are basic in nature, with pH value more than 7. 2.4....
Class X Science Science 2 already come to know that chlorine is produced during the electrolysis of aqueous sodium chloride (brine). This chlorine gas is used for the manufa...
Class X Science Science 2 Sodium hydrogencarbonate is also an ingredient in antacids. Being alkaline, it neutralises excess acid in the stomach and provides relief. (iii) It...
Class X Science Science 2 Waterofcrystallisationisthefixednumberofwatermoleculespresentinoneformula unit of a salt. ■ Salts have various uses in everyday life and in industr...
Class X Science Science 2 Equal lengths of magnesium ribbons are taken in test tubes A and B. Hydrochloric acid (HCl) is added to test tube A, while acetic acid (CH COOH) is...
Class X Science Science 2 extinguisher The reaction of acids with metal hydrogencarbonates is used in the fire extinguishers which produce carbon dioxide. ■ Take 20 mL of so...