Saturday, August 4, 2012

Guess Question Paper SCIENCE Class-10 Chapter 3. Metal and Non-metals

CBSE Guess Question Paper SCIENCE Class-10 Chapter 3. Metal and Non-metals
Q.1 Write an activity to show that ionic compounds are good conductors of electric current in their aqueous solution.
Q.2. Why is aluminum extracted from alumina by electrolytic reduction and not by reducing with carbon?
Q.3 Define the terms:(i) Mineral (ii) Ore and (iii) Gangue
Q.4. 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.5 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,6 What would you observe when zinc is added to a solution of iron (II) sulphate? Write the chemical reaction that takes places.
Q.7.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.8. Write a balanced chemical equation for the reaction of the following metals with water: (i) Ca (ii) Zn (iii) Fe
Q.9. 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.10. 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.11. 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 metal or a non metal.
Q.12 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.13 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.14 Why is ZnO called an amphoteric oxide? Give the support to your answer.
Q.15 Answer :
a. Write the electron dot structure for oxygen and magnesium.
b.  Show the formation of Na2O and CaO by the transfer of electrons.
Q.16 Give equation for the following
(a) Iron is heated with steam.
(b) Magnesium reacts with water.
(c) iron reacts with dil.HCl
Q.17 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.18 Which gas is always produced when a metal reacts with a dilute Write chemical reaction when iron reacts with dil. H2SO4.
Q.19. What is the activity series of metals? Rearrange the following metals in an increasing order of reactivity: Aluminum, Zinc, Mercury.
Q.20 What is meant by the term ‘enrichment of ore’ ? name four Methods generallyused for enrichment of ores.
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CBSE Guess Question Paper : Metal and Non-metals-1
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CBSE Guess Question Paper : Metal and Non-metals-3
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