Of the three metals X, Y and Z, X reacts with cold water, Y with hot water and Z with steam only. Identify X, Y and Z and also arrange them in order of increasing reactivity
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0
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10949
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March 18, 2018
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When a metal X is treated with cold water, it gives a basic salt Y with molecular formula XOH (Molecular mass = 40)
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0
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26668
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March 18, 2018
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Explain the following statements: Some alkali metals can be cut with a knife
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0
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3974
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March 18, 2018
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Give reasons: (i) Reactivity of A1 decreases if it is dipped in HN03
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0
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727
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March 18, 2018
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Name two metals which react violently with cold water. Write any observation you would make when such a metal is dropped into water
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0
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13611
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March 18, 2018
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Why are food cans tin-plated instead of zinc plated though zinc is cheaper than tin?
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0
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4378
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March 16, 2018
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Why is aluminium oxide considered an amphoteric oxide?
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0
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6862
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March 16, 2018
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Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken
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0
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1944
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March 16, 2018
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What would happen to iron railings on the road side if they are not painted?
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0
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2193
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March 16, 2018
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What is 24-carat gold? How will you convert it into 18-carat gold?
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0
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3482
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March 16, 2018
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Why should the metal sulphides and carbonates be converted to metal oxides in the process of extraction of metal from them?
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0
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4490
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March 16, 2018
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What is a thermit reaction? State one use of this reaction
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0
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2914
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March 16, 2018
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The following reaction takes place when aluminium powder is heated with MnO2
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0
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5092
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March 16, 2018
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An ore gives carbon dioxide on treatment with a dilute acid
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0
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977
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March 16, 2018
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State the reason for the following behaviour of zinc metal:
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0
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1500
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March 16, 2018
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List any two observations when a highly reactive metal is dropped in water
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0
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6518
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March 16, 2018
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Which of the following reactions will not occur? Give reasons
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0
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956
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March 16, 2018
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Name a metal for each case:
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0
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846
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March 16, 2018
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What happens when (i) iron nail is placed in silver nitrate solution? (ii) iron strip is dipped in zinc sulphate solution?
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0
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4329
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March 16, 2018
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Metals replace hydrogen from dilute acids, whereas non-metals do not. Why?
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0
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9150
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March 16, 2018
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Generally, when metals are treated with mineral acids, hydrogen gas is liberated but when metals
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0
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761
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March 16, 2018
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A zinc plate was kept in a glass container having copper sulphate solution
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0
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4762
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March 16, 2018
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Name one metal and one non-metal that exist in liquid state at room temperature
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0
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1536
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March 16, 2018
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Give two examples each of the metals that are good conductors and poor conductors of heat respectively
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0
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1984
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March 16, 2018
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Explain why the surface of some metals acquires a dull appearance when exposed to air for a long time
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0
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3940
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March 16, 2018
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