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We can see the sun even when it is little below the horizon because of ______.
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Answer the following:
Explain the role of latent heat in the change of state of a substance.
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Liquid ammonia is used in ice factory for making ice from water. If water at 20°C is to be converted into 2 kg ice at 0°C, how many grams of ammonia are to be evaporated? (Given: The latent heat of vaporization of ammonia = 341 cal/g)
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A thermally insulated pot has 150 g ice at temperature 0°C. How much steam of 100°C has to be mixed to it, so that water of temperature 50°C will be obtained? (Given : latent heat of melting of ice = 80 cal/g, latent heat of vaporization of water = 540 cal/g, specific heat of water = 1 cal/g °C)
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Who will spend more electrical energy? 500 W TV Set in 30 mins, or 600 W heater in 20 mins?
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Write name.
Alloy of sodium with mercury.
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Molecular formula of the common ore of aluminium.
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The oxide that forms salt and water by reacting with both acid and base.
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The device used for grinding an ore.
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The nonmetal having electrical conductivity.
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The reagent that dissolves noble metals.
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Write scientific reason.
Generally the ionic compounds have high melting points.
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Write scientific reason.
Sodium is always kept in kerosene.
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Write scientific reason.
Pine oil is used in froth flotation.
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Write scientific reason.
Anodes need to be replaced from time to time during the electrolysis of alumina.
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When a copper coin is dipped in silver nitrate solution, a glitter appears on the coin after some time. Why does this happen? Write the chemical equation.
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The electronic configuration of metal ‘A’ is 2,8,1 and that of metal ‘B’ is 2,8,2. Which of the two metals is more reactive? Write their reaction with dilute hydrochloric acid.
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When a liquid is getting converted into solid, the latent heat is ………………………………
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Find the odd one out and justify it.
Fuse wire, M.C.B., Rubber Gloves, Generator
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Molecular formula of the chloride of an element X is XCl. This compound is a solid having high melting point. Write name of any element present in the same group as X
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