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Q.1. Why is sodium kept immersed in kerosene oil?
Q.2. Name two metals which are found in nature in the free state.
Q.3. What chemical process is used for obtaining a metalfrom its oxide.
Q.4. Which metals do not corrode easily?
Q.5. Why copper is used to make hot water tanks and not steel .
Q.6. What is an alloy? Name the constituents of 22-carat gold. Why is 24-carat gold converted to 22-carat gold?
Q.7. Why are metals good conductors of electricity?
Q.8 Give reasons for the following: (a) Zinc oxide is considered as amphoteric oxide. (b) Non-metals in general do not displace hydrogen from dilute acids. (c) Metals conduct electricity.
Q.9 Show that both air and water are necessary for corrosion of iron.
Q.10 Explain why: (i)iron sheets are coated with zinc. (ii)we apply paint on iron articles. (iii)the galvanized iron article is protected against rusting even if the zinc layer is broken.
Q.11 (i) What is an ‘activity series of metals’? Arrange themetals Zn, Mg, Al, Cu and Fe in a decreasing order of reactivity. (ii) What would you observe when you put (a) Some zinc pieces into blue copper sulhate solution?
(b) Some copper pieces into green ferrous sulphate solution? (c ) Name a metal which combines with hydrogen gas. Name the compound formed.
Q.12. State two ways to prevent the rusting of iron.
Q.13. What type of oxides are formed when non-metalscombine with oxygen?
Q.14. Name a metal which is both ductile as well as malleable.
Q,15. Write the chemical equation to represent the reaction taking place when copper oxide is heated in a stream of hydrogen.
Q.16. The reaction of a metal X with Fe2O3 is highlyexothermic and is used to join broken railway tracks. Identifymetal X. Write the chemical equation of its reaction with Fe2O3.
Q.17 NIKITA took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test-tube over it. .i) What will be the action of gas an (a) dry litmus paper? (b) Moist litmus paper?
(ii) Write a balanced chemical equation for the reaction taking place.
Q.18 Why do ionic compounds have high melting points?
Q.19. Give reasons:(i) Platinum, gold and silver are used tomake jewellery.
(ii) Sodium, potassium and lithium are stored under oil.
(iii) Aluminium is a highly reactive metal, still it is used tomake utensil.
Q.20 (i) What is corrosion of metals? Name one metal which does not corrode and one which corrodes on being kept in atmosphere.
Q.21 Write an activity to show that ionic compounds are good conductors of electric current in their aqueous solution.
Q.22. Why is aluminium extracted from alumina by electrolytic reduction and not by reducing with carbon?
Q.23 Define the terms:(i) Mineral (ii) Ore and (iii) Gangue
Q.24. Explain how the following metals are obtained from their compounds by the reaction process: (i) Metal ‘X’ , which is low in reactivity series.
(ii) Metal ‘Y’, which is middle in reactivity series.
(iii) Metal ‘Z’ which is high up in the reactivity series.
Q.25 Give reasons:
(i) The surface of some metals acquires a dull appearance when exposed to air for a long time.(ii) A salt which does not conduct electricity in the solid state becomes a good conductor in molten state ..
Q,26 What would you observe when zinc is added to a solution of iron (II) sulphate? Write the chemical reaction that takes places.
Q.27.You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.
Q.28. Write a balanced chemical equation for the reaction of the following metals with water: (i) Ca (ii) Zn (iii) Fe
Q.29. What will happen if a :
(i) Strip of zinc is immersed in a solution of copper sulphate.
(ii) Strip of copper is kept immersed in a solution of silver nitrate.Q.30. Explain why: (i) Conc. HNO3 can be stored in aluminium container.
(ii) Aluminium is used for making transmission wires.
(iii) 24 carat gold can not be used for making ornaments.
(iv) Aluminium is used for making cooking utensils.
(v) Metals generally do not form compounds with hydrogen.
Q.31. An element X on reacting with O2 forms X2O.This Oxide dissolves in water and turns blue litmus paper red. Predict the nature of element whether it is a metalor a non metal.
Q.32 An element E combines with O2 to form an oxide E2O, which is a good conductor of electricity. Answer the following:
i) How many electrons will be present in the outer most shell of E?
ii) Write the formula of the compound formed when it combines with Chlorine.
Q.33 Name one electrovalent compounds in each case in which ;
(i)One atom combines with one other atom (ii)One atom combines with two other atoms (iii)One atom combines with three other atoms
Q.34 Why is ZnO called an amphoteric oxide? Give the support to your answer. Q.35 [ I ]Write the electron dot structure for oxygen and magnesium. [ ii ] Show the formation of Na2O and CaO by the transfer of electrons.
Q.36 Give equation for the following (a) Iron is heated with steam.
(b) Magnesium reacts with water. [c] iron reacts with dil.HCl
Q.37 A trivalent metal X is manufactured by the process of electrolysis, It is the most abundant metal in the earth’s crust. Identify the metal and state its two uses.
Q.38 Which gas is always produced when a metal reacts with a dilute Write chemical reaction when iron reacts with dil. H2SO4.
Q.39What is the activity series of metals? Rearrange the following metals in an increasing order of reactivity: Aluminium, Zinc, Mercury.
Q.40 What is meant by the term ‘enrichment of ore’ ? name four Methods generallyused for enrichment of ores.
Q.1. Why is sodium kept immersed in kerosene oil?
Q.2. Name two metals which are found in nature in the free state.
Q.3. What chemical process is used for obtaining a metalfrom its oxide.
Q.4. Which metals do not corrode easily?
Q.5. Why copper is used to make hot water tanks and not steel .
Q.6. What is an alloy? Name the constituents of 22-carat gold. Why is 24-carat gold converted to 22-carat gold?
Q.7. Why are metals good conductors of electricity?
Q.8 Give reasons for the following: (a) Zinc oxide is considered as amphoteric oxide. (b) Non-metals in general do not displace hydrogen from dilute acids. (c) Metals conduct electricity.
Q.9 Show that both air and water are necessary for corrosion of iron.
Q.10 Explain why: (i)iron sheets are coated with zinc. (ii)we apply paint on iron articles. (iii)the galvanized iron article is protected against rusting even if the zinc layer is broken.
Q.11 (i) What is an ‘activity series of metals’? Arrange themetals Zn, Mg, Al, Cu and Fe in a decreasing order of reactivity. (ii) What would you observe when you put (a) Some zinc pieces into blue copper sulhate solution?
(b) Some copper pieces into green ferrous sulphate solution? (c ) Name a metal which combines with hydrogen gas. Name the compound formed.
Q.12. State two ways to prevent the rusting of iron.
Q.13. What type of oxides are formed when non-metalscombine with oxygen?
Q.14. Name a metal which is both ductile as well as malleable.
Q,15. Write the chemical equation to represent the reaction taking place when copper oxide is heated in a stream of hydrogen.
Q.16. The reaction of a metal X with Fe2O3 is highlyexothermic and is used to join broken railway tracks. Identifymetal X. Write the chemical equation of its reaction with Fe2O3.
Q.17 NIKITA took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test-tube over it. .i) What will be the action of gas an (a) dry litmus paper? (b) Moist litmus paper?
(ii) Write a balanced chemical equation for the reaction taking place.
Q.18 Why do ionic compounds have high melting points?
Q.19. Give reasons:(i) Platinum, gold and silver are used tomake jewellery.
(ii) Sodium, potassium and lithium are stored under oil.
(iii) Aluminium is a highly reactive metal, still it is used tomake utensil.
Q.20 (i) What is corrosion of metals? Name one metal which does not corrode and one which corrodes on being kept in atmosphere.
Q.21 Write an activity to show that ionic compounds are good conductors of electric current in their aqueous solution.
Q.22. Why is aluminium extracted from alumina by electrolytic reduction and not by reducing with carbon?
Q.23 Define the terms:(i) Mineral (ii) Ore and (iii) Gangue
Q.24. Explain how the following metals are obtained from their compounds by the reaction process: (i) Metal ‘X’ , which is low in reactivity series.
(ii) Metal ‘Y’, which is middle in reactivity series.
(iii) Metal ‘Z’ which is high up in the reactivity series.
Q.25 Give reasons:
(i) The surface of some metals acquires a dull appearance when exposed to air for a long time.(ii) A salt which does not conduct electricity in the solid state becomes a good conductor in molten state ..
Q,26 What would you observe when zinc is added to a solution of iron (II) sulphate? Write the chemical reaction that takes places.
Q.27.You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.
Q.28. Write a balanced chemical equation for the reaction of the following metals with water: (i) Ca (ii) Zn (iii) Fe
Q.29. What will happen if a :
(i) Strip of zinc is immersed in a solution of copper sulphate.
(ii) Strip of copper is kept immersed in a solution of silver nitrate.Q.30. Explain why: (i) Conc. HNO3 can be stored in aluminium container.
(ii) Aluminium is used for making transmission wires.
(iii) 24 carat gold can not be used for making ornaments.
(iv) Aluminium is used for making cooking utensils.
(v) Metals generally do not form compounds with hydrogen.
Q.31. An element X on reacting with O2 forms X2O.This Oxide dissolves in water and turns blue litmus paper red. Predict the nature of element whether it is a metalor a non metal.
Q.32 An element E combines with O2 to form an oxide E2O, which is a good conductor of electricity. Answer the following:
i) How many electrons will be present in the outer most shell of E?
ii) Write the formula of the compound formed when it combines with Chlorine.
Q.33 Name one electrovalent compounds in each case in which ;
(i)One atom combines with one other atom (ii)One atom combines with two other atoms (iii)One atom combines with three other atoms
Q.34 Why is ZnO called an amphoteric oxide? Give the support to your answer. Q.35 [ I ]Write the electron dot structure for oxygen and magnesium. [ ii ] Show the formation of Na2O and CaO by the transfer of electrons.
Q.36 Give equation for the following (a) Iron is heated with steam.
(b) Magnesium reacts with water. [c] iron reacts with dil.HCl
Q.37 A trivalent metal X is manufactured by the process of electrolysis, It is the most abundant metal in the earth’s crust. Identify the metal and state its two uses.
Q.38 Which gas is always produced when a metal reacts with a dilute Write chemical reaction when iron reacts with dil. H2SO4.
Q.39What is the activity series of metals? Rearrange the following metals in an increasing order of reactivity: Aluminium, Zinc, Mercury.
Q.40 What is meant by the term ‘enrichment of ore’ ? name four Methods generallyused for enrichment of ores.
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