1. Before burning in air, the magnesium ribbon is cleaned by rubbing with a sandpaper to:a. Make the ribbon surface shinierb. Remove the layer of magnesium oxide from the ribbon surfacec. Remove the layer of magnesium carbonate from the ribbon surfaced. Remove the moisture from the ribbon surface2. In a chemical reaction between sulphuric acid and barium chloride solution thewhite precipitates formed are of:a. Hydrochloric acidb. Barium sulphatec. Chlorined. Sulphur3. The respiration process during which glucose undergoes slow combustion bycombining with oxygen in the cells of our body to produce energy, is a kind of:a. Exothermic processb. Endothermic processc. Reversible processd. Physical process4. A chemical reaction does not involve:a. Formation of new substances having entirely different properties than that of thereactantsb. Breaking of old chemical bonds and formation of new chemical bondsc. Rearrangement of the atoms of reactants to form new productsd. Changing of the atoms of on element into those of another element to form newproducts5. One of the following processes does not involve a chemical reaction. That is:a. Melting of candle wax when heatedb. Burning of candle wax when heatedc. Digestion of food in our stomachd. Ripening of banana6. It is necessary to balance a chemical equation in order to satisfy the law of:a. Conservation of motionb. Conservation of momentumc. Conservation of energyd. Conservation of mass7. All the methods mentioned below can be used to prevent the food from gettingrancid except:i. Storing the food in the air-tight containersii. Storing the food in refrigeratoriii. Keeping the food in clean and covered containersiv. Always touching the food with clean handsa. (i) and (ii)b. (i) and (iii)c. (i), (iii) and (iv)d. (iii) and (iv)8. Rusting of iron involves a chemical reaction which is a combination of:a. Reduction as well as combination reactionsb. Oxidation as well as combination reactionsc. Reduction as well as displacement reactionsd. Oxidation as well as displacement reactions9. You are given the following chemical reaction:Heat 2 2 CuO + H Cu + H OThis reaction represents:a. Combination reaction as well as double displacement reactionb. Redox reaction as well as displacement reactionc. Double displacement reaction as well as redox reactiond. Decomposition reaction as well as displacement reaction10. When ferrous sulphate is heated strongly it undergoes decomposition to formferric oxide as a main product accompanied by a change in colour from:a. Blue to green.b. Green to blue.c. Green to brown.d. Green to yellow.11. Which of the following gases is used in the storage of fat and oil containingfoods for a long time?a. Carbondioxide gasb. Nitrogen gasc. Oxygen gasd. Neon gas12. The displacement reaction between iron (III) oxide and a metal X is used forwelding the rail tracks. Here X is:a. Copper granulesb. Magnesium ribbonc. Sodium pelletsd. Aluminium dust13. The neutralization reaction between an acid and a base is a type of:a. Double displacement reactionb. Displacement reactionc. Addition reactiond. Decomposition reaction14. The chemical reaction between Hydrogen sulphide and iodine to giveHydrogen iodide and sulphur is given below:2 2 H S + I 2HI + SThe reducing and oxidizing agents involved in this redox reaction are:a. Iodine and sulphur respectivelyb. Iodine and hydrogen sulphide respectivelyc. Sulphur and iodine respectivelyd. Hydrogen sulphide and sulphurChapter 2ACIDS BASE AND SALTS1. Some fruits like mango, lemon, raw grapes, orange, etc., have a sour taste due tothe presence of:a. Acetic acidb. Citric acidc. Lactic acidd. Oxalic acid2. Zinc granules on treating with an acid X, form the zinc sulphate (ZnSO4) saltalong with the evolution of a gas Y which burns with a pop sound when broughtnear to a burning candle. Identify the acid X and gas evolved Y.a. X- Sulphuric acid and Y- Oxygen gasb. X- Hydrochloric acid and Y- Oxygen gasc. X- Sulphuric acid and Y- Hydrogen gasd. X- Hydrochloric acid and Y- Hydrogen gas3. The figure given below represents the experiment carried out between conc.sulphuric acid and sodium chloride, which react with each other to form HCl gas.Blue litmus paper is brought near the mouth of the delivery tube to check thepresence of HCl acid but no change is observed in the color of litmus paperbecause:a. The litmus paper used is dryb. The litmus paper used is moistc. Blue litmus paper does not change its color with an acidd. The litmus paper is kept very close to the mouth of the delivery tube