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|, , u, , , , 6. List five cach opaque and transparent materials., Ans: Opaque materials: Wood, iron, carbon, brick, gold., Transparent matoriais: Water, glass, air and fibre glass, 7. Why water is called universal solvent?, Ans: The property of water to dissolve large number of materials makes it, a universal solvent., 8. List three liquids which are miscible and immiscible in water,, Ans: 1. Miscible in water: Milk, glycerin and soft drinks., 2. Immiscible in water: Edible oll, kerosene and petrol,, 9. On which basis are the various objects grouped?, , Ans: The grouping of various objects can be done on the basis of the, following characters., , *Size * Solubility in water, *Shape * Attraction towards magnet, *Colour * Conduction of heat, *Hardness * Transparency ete..., , 10. List the following substances as soluble and insoluble in water., { sand, salt, sugar, paint, chilli powder, ghee, blotting paper ), Ans; Water soluble substances: salt, sugar., Water insoluble substance: sand paint, chilli powder,, ghee, blotting paper., , 11. Show that sugar, common salt are soluble while chalk powder and, , sand are insoluble in water., , Ans: Take four test tubes, fill each of them about half with « water, Keep, each of them in a test tube stand. Add pinch of each of four substances in, separate test tube. Shake well and allow to stand for few minutes., , Common salt, sugar dissolve while chalk powder and sand do not, dissolved., , 12, Name two gases each whi, Ans: Gases soluble in water: Oxygen and carbon dioxide., , ich are soluble and insoluble in water., , Gases insoluble in water: Hydrogen and Nitrogen.