METALLURGY - 10 ICSE CHAPTER WISE QUESTIONS

   METALLURGY

                            

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 Short answer Questions

1.  Name (a) a metal which is lighter than water.           

   (b) a metallic oxide which cannot be reduced by hydrogen or carbon monoxide.

2.  Name an alloy of (a) Aluminium used in aircraft construction.         

  (b) Lead used in electrical wiring or electrical work in joining metals.       

  (c) Cu used in electrical appliances or household vessels.

3.  What is (a) galvanized iron.    (b) passive iron

4.  (a) Name an alloy of Zn used in simple voltaic cells.

     (b) Zincite is an ore of zinc. Name two other ores of zinc from which it is extracted.

     (c) give the balanced chemical equations of the reactions which take place during the exatraction of Zn from the ores you have mentioned.

5.  In the laboratory, metallic sodium is stored in kerosene oil. Give reasons.

6.  State two ways to prevent rusting.

7.  (a) Name a meatl which occurs free in nature.           

     (b) Write balanced equations for the extraction of Zn from zinc blende.

8.  Explain why carbon can reduce copper(II)oxide to copper but not calcium oxide to calcium.

9.  Account for the following fact: though lead is above hydrogen in the activity series, it does not react with dilute hydrochloric acid or sulphuric acid.

10.  Differentiate between the following

     (a) Roasting and calcinations.  (b) Mineral and Ore.

11.  Explain why aluminium cannot be obtained by the reduction of its oxide with carbon.

12.  What is the function of cryolite in the extraction of Al, other than as a solvent for bauxite?

13.  What is the special features of each of the following:           

    (a) Duralumin  (b) type metal

14.  By which chemical process are the impurities present in the iron    

     obtained from blast furnace removed during making of steel?

15.  Which substance is added to steel to make stainless steel?

16.  Zinc blende, when roasted in air, gives off a gas which, if allowed to escape, would constitute an atmospheric pollutant. Wht is this gas?

17.  A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him, which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but, after a futile argument, the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?

18.  Give reasons why Cu is used to make hot water tanks and not steel.

Long Answer Questions

1.  (a) What is an ore?     

     (b) Name the two ores ore which Al is extracted by electrolysis.     

     (c) Write down the equations of the reactions which take place during the extraction of Al.

2.  (a) How is steel prepared from pig iron?       

     (b) What is the function of cryolite in the extraction of Al, other than as a solvent for bauxite?

3.  (a) Give the formula of an ore of zinc.

     (b) Write the balanced chemical equations for the following steps in the extraction of zinc: (i) Roasting of the ore.           

     (ii) Reduction of the zinc compound which is the product of the above reaction.           

    (c) What, in addition to a zinc compound, is added to the blast furnace?         

    (d) State one large scale use of zinc.

4.  (a) Place calcium, iron, Magnesium and sodium metals in order of their activity with water, placing the most reactive first.  

     (b) write equations for each of the above metals which react with water.

5.  The following questions refer to the extraction of Aluminium and Iron from their ores      

    (a) Name the principal ore from which (i) Iron and (ii) Al are extracted.               

    (b) What is the most imp chemical process in the extraction of any metal? State how the essential step is carried out in the extraction of (i) Iron and (ii) Al                   

    (c) Iron and Al ores both contain impurities. Explain briefly how these impurities are removed in each case.                                                                                    

    (d) What is the major impurity present in Iron when it is removed from blast furnace?        

    (e) Name an alloy of Zn used in Voltaic cell?

6.  Explain the significance of the following substances in the extraction of aluminium:           (a) Bauxite      (b) NaOH (c) Cryolite      (d) Graphite

7.  (a) Define or explain the meaning of the term ‘ore’. 

     (b) the following substances are put into blast furnace when    

          manufacture iron: iron ore, coke, limestone and hot air:          

 (i) what is name of the most common ore of Iron and what is its chemical formula?     

(ii) what is the purpose of using (1) the coke and (2) the limestone?                  

(iii) write the equation for the reduction reaction which produces Iron.                   

(iv) Name two substances which separate at the bottom of the blast furnace.

8.  (a) Complete the table given below which compares some properties of metals and non metals:  

     (b) (i) Haematite is an important ore of the metal iron. What is the name of the iron compound in haematite?         

     (ii) Name the reducing agent that converts the iron compound in haematite to iron.     

    (iii) Name the main impurity present in iron obtained from the blast furnace.           

    (iv) Name the purest form of iorn.

9.  (a) Write balance equation for the following reaction: Zn and dil.H2SO4                           

     (b) (i) Cast iron contains about 4% Carbon. By what chemical process is the amount of Carbon decreased to make steel?  (ii) which metal is added to steel to make stainless steel?

10.  (a) With reference to the reduction of copper oxide, iron(II)oxide, lead(II)oxide and Magnesium oxide by hydrogen, place the oxides in order of increasing case of reduction. That is, put first the oxide that is most difficult to reduce, and last, the oxide that is most easily reduced.  

     (b) Write the balanced equations for the following reactions:    (i) Reduction of copper oxide by hydrogen.  (ii) Reduction of iron(III)oxide by carbon monoxide.       (iii) Reduction of lead(II)oxide by carbon.               

    (c) What metallic property is shown by the non metallic graphite?

11.  Answer the following questions:      

    (a) Name the process used for the reduction of alumina.    

    (b) Name the anode, cathode and electrolyte used in the process mentioned in (a).        

    (c) Why is cryolite used in the extraction of Al from Al2O3.           

    (d) Why are the anodes replaced periodically in the process mentioned in (a)?

12.  (a) Why is lime stone added to the blast furnace in the extraction of iron from haematite? 

      (b) Name the reducing agent in the extraction of iron from haematite in the blast furnace.           

      (c) How is the reducing agent in the extraction of iron from haematite in the blast furnace?

13.  (a) Name the principal ore of aluminium.      

     (b) Name the process use for removing the impurities like iron oxide from the above ore.     

     (c) Write the chemical equations for the reactions at the cathode and the anode.

14.  Al is manufactured from aluminium oxide. Aluminium oxide is dissolved in molten cryolite and this solution is electrolysed.           

      (a) Name the gas formed at the anode.          

     (b) Name the material of the anode.  

     (c) Write the chemical equations for the reactions at the cathode and the anode.

15.  Iron is extracted from haematite, an oxide of iron, in the blast furnace.                               

     (a) name the substance s fed into the blast furnace.           

     (b) Name the reducing agent that reduces the oxide of iron to iron.

16.  Explain why aluminium is extracted by electrolysis, whereas iron is not.

17.  The following is the decreasing order of reactivity for a number of elements: Na, Zn, Fe, H, Cu & Ag. From the above list, select  

      (a) a metal that has to be stored under oil.           

     (b) a metal that reacts with water to give hydrogen and an alkali.    

     (c) one metal that could be obtained by the reduction of its oxides with metals. 

     (d) two metals forming hydroxides that decompose on heating.          

     (e) two metals which will not react with steam.

18.  (a) Name a non metallic element that

     (i) forms acidic and neutral oxides.   

     (ii) has a metallic lustre.                     

     (iii) is a liquid at room temperature    

     (iv) is a conductor of electricity.        

     (b) The blast furnace is used to extract iron from iron ore. Along with iron ore, other substances are put into the blast furnace.     

     (i) Which substance is put into the blast furnace for the reduction of iron ore?

     (ii) The iron ore contains impurities such as silica and earthy impurities. Which substance is put into the blast furnace to remove these impurities?      

     (iii) In the blast furnace, what makes up the blast?

19.  (a) With respect to the reduction of pure alumina in the electrolytic cell, answer the following questions:       

      (i) What is the name of the process?

     (ii) What is the physical state of Al in which it is taken out from the electrolytic cell?        

     (iii) Name the substance presemt in the electrolytic mixture.

     (iv) Why is a layer of powdered coke sprinkled over the surface of the electrolytic mixture?

     (b) Aluminium occurs in the earth crust as bauxite which is an impure form of alumina.                 

      I. Name two main impurities present in alumina.  

     Ii. What is the name of the process by which the impurities mentioned in (i) are removed?

     (c) Name an alloy of aluminium used for making aeroplanes and scientific instruments.

 

Conceptual questions

1.  What is the percentage of silver in ‘German Silver’

2.  What is the role of limestone in the extraction of iron?

3.  Among the metals aluminium, silver, gold and iron, which one is protected by a layer of its own oxide?

4.  Why is zinc not extracted from Zinc Oxide through reduction using CO?

5.  Two elements X and Y are stored under water and kerosene oil, respectively. When small piece of each element is left open in air, both start warming up. The product in each case is dissolved in water. The solution from the residue X was found to be acidic while that of residue Y was basic.                                  

     A. identify elements X and Y. support your answer with suitable explanation.       

     B. Write the balanced equation for the reaction of elements X and Y on exposure to air

     C. Write balanced equation for reaction of products formed in (B) with H2O

6.  A certain metal does not liberate hydrogen from dil.H2SO4 but it displaces Cu from aq. CuSO4. State the most likely place for the metal in the activity series.

7.  A metal ‘A’ in the form of turnings reacted with a hot con.dibasic acid H2B and produces a deep blue solution of salt AB. When a wire of metal C is put in the solution of AB, the deep blue colour gets slowly discharged leaving behind a colourless CB salt solution and A was generated. Identify A, H2B, AB, C and CB, and also, explain the observations.

8.  Give reason for the following:          

     a. Nitric acid can be stored in an Al container but NaOH cannot be sotored in it.       

     b. Al is more abundant than gold in the earth crust, yet it is gold and not Al that has been known to man since ancient times.

9.  Explain the following:                                                   

     a. Cast iron is used to make castings.        

     b. Zinc is used in dry cells and to make alloys   

     c. a mixture of Al powder and linseed oil is used to paint iron poles.                

     d. Thin Al foils are used in food packing                                                                 

     e. Metals act as reducing agents.       

           Previous year ICSE Examination questions

Short Answer Questions

1.  What do you observe when carbon monoxide is passed over copper oxide.

2.  Match from the following list of substances (A) to (E), the description given below:         

      A. Sulphur                                   B. Silver Chloride               

      C. Hydrogen Chloride               D. Copper(II)sulphate            

     E. Graphite.                                                                    

      A non metal which is a good conductor of electricity.

3.  State the property of the metal being utilized in the following:   

Uses of metal	Property
Zinc in galvanization
Aluminium in thermite welding

4.  Find the odd out and explain your choice. Cu, Pb, Zn and Hg.

5.  Correct the following statement:   

     Haematite is the chief ore of aluminium.

6.  Name the following  

      a. A metal which is a liquid at room temperature. 

      b. A compound which is added to lower the fusion temperature of the electrolytic bath in the extraction of aluminium.    

     c. The process of heating an ore to a high temperature in the presence of air.          

     d. The compound formed by the reaction between Calcium Oxide and Silica.  e. The middle region of the blast furnace.

7.  Choose the major metals from the following list to make the alloys given below:   Ca, Cu, Pb, Al, Zn, Cr, Mg and Fe.      

      A. Stainless Steel        B. Brass

8.  a. Iron and chromium are used to make stainless steel.                     

b. Name a non metal that has a metallic lustre and sublimes on heating.

9.  In the manufacture of iron, a mixture of limestone, coke and iron ore is added to the blast furnace. In this context, give the equation for the reduction of iron ore.

10.  a. To protect iron from rusting it is coated with a thin layer of zinc. Name this process

b. Name a non metal that has a metallic lustre and sublimes on heating.

11.  Write a balanced chemical equation for the reaction of aluminium powder with hot and concentrated caustic soda solution.

12.  a. Among the metals copper, iron, magnesium, sodium and zinc, select a metal that           

      i. does not react with dilute hydrochloric acid.   

     Ii. Can form +2 and +3 ions.       

     Iii. Has a Hydroxide that reacts with both acids and alkalis.  

     Iv. Does not react with cold water, but reacts with steam  when heated.

     b. Arrange the metals of (a) in decreasing order of reactivity.

13.  Name the Zinc compound in Zinc blende.

14.  Write the balanced equation for the following reaction: Zn + NaOH

Long Answer Questions

1.  Answer the following questions                  

     a. Name a metal which is found abundantly in the earth’s crust.

     b. What is the difference between calcination and roasting?

     c. Name the process used for the enrichment of sulphide ore.

     d. Write the chemical formulae of one main ore of iron and Al.

     e. Write the constituents of electrolyte for the extraction of Al.

2.  Name the main constituents metal in the following alloys:       

     a. Duralumin.              b. Brass           c. Stainless Steel        

3.  The sketch given below illustrates the refining of aluminium by Hoope’s process:

     a.   Which of A and B is the cathode and which one is the anode?

     b.  What is the electrolyte in the tank?

     c.   What material is used for the cathode?

4.  The following is a sketch of an electrolytic cell used in the extraction of aluminium

     a.   What is the substance of which the electrodes A and B are made?

     b.  At which electrode(A or B) is the aluminium formed?

     c.   What are the two aluminium compounds in the electrolyte C?

     d.  Why is it necessary for electrode B to be continuously replaced?

5.  The following is an extract from ‘Metals in the service of Man, Alexander and Street/Pelican 1976’  alumina has a very high m.p of over 2000 ⁰C so that it cannot readily be liquefied. However, conversion of alumina to aluminium and oxygen, by electrolysis, can occur when it is dissolved in some other substance.

     a.   Which solution is used to react with bauxite as the first step in obtaining pure aluminium oxide?

     b.  The aluminium oxide for the electrolytic extraction of aluminium is obtained by heating aluminium hydroxide. write the balanced chemical equation, for this reaction.

     c.   Name the element which serves both as the anode and the cathode in the extraction of aluminium.

     d.  Write the balanced chemical equation for the reaction which occurs at the cathode during the extraction of aluminium by electrolysis.

     e.   Give the balanced chemical equation for the reaction which occurs at the anode when aluminium is purified by electrolysis.

6.  From the list of characteristics given below, select the five which are relevant to non-metals and their compounds:

     a.   Ductile      b. Conduct electricity c. Brittle              d. Acidic oxides          e. Basic oxides   f.   Discharged at anode       g. Discharged at cathode           h. Ionic chlorides       

      i. Covalent Chlorides     j. Reaction with dil.H2SO4 yields H2        

     k. 1,2 of 3 valence electrons  l. 5,6 or 7 valence electrons   

7.  Name the following:  

     a.   (i) A metal which is liquid at room temperature.

     (ii) A compound which is added to lower the fusion temperature of the electrolyte bath in the extraction of aluminium.

     (iii) The process of heating an ore to a high temperature in the presence of air.

     (iv) The compound formed by the reaction between calcium oxide and silica.

     b.  (i) Name the oxide which acts as a flux in the blast furnance.

     (ii) Is the amount of carbon in pig iron / cast iron more than, less than or the same as the amount of carbon is steel?

     (iii) Name an allotrope of a non metal that allows an electricity to pass through it.

     c.   Fill in the blanks with the substances given in the below   

        CO, CO2, Coal, Coke, Lime, FeO, Fe2O3, Lime stone.   

     The raw materials required for the extraction of iron from haematite ore (i) _____________      (ii) _________________ and hot air. The mineral present in haematite is (iii) ____________         Which is reduced by (iv) ________________ to iron.

8.  (A) to (F) given below relate to the source and extraction of either zinc or aluminium:                               

     A. Bauxite                                       B. Coke                       C.Cryolite      

     D. Froth floatation                       E. NaOH                      F. ZnS

     a.   Write down the three letters for each, from the above list, which are relevant to (i) Zn, and (ii)Al.

     b.  Fill in the blanks using the most appropriate words from (A) to (F). (i) The ore from which aluminium is extracted must first be treated with _________________ solution so that pure aluminium oxide can be obtained.                                                                                

     (ii) Pure aluminium oxide is dissolved in ______________ to make a conducting solution.

9.  (a) i. Name the ore of Zinc containing its sulphide.

     ii. In the process of extracting Zinc, the above named ore is roasted. Write the balanced chemical equation for the reaction which takes place when the sulphide ore is roasted.

     iii. Name the substance used to reduce the roasted ore. Write the balanced chemical equation for the reaction.

     iv. ‘Iron is removed from a blast furnace as a liquid.’ State how zinc leaves the furnace.

     (b) Write the balanced chemical equation for the reaction of Zinc with each of the following  i. NaOH                    ii. Dil.H2SO4      iii.CuSO4

10.  Aluminium is extracted from its chief ore, bauxite. The ore is first purified and then the metal is extracted from it by electrolytic reduction.                                                                                           

     a.   Write three balanced chemical equations for the purification of bauxite by Hall’s process.

     b.  Name a chemical used for dissolving aluminium oxide. In which state of sub- division is the chemical used?

     c.   Write an equation for the reaction which takes place at the anode during the extraction of aluminium by the electrolysis process.

     d.  Mention one reason for the use of aluminium in thermite welding.

11.  Compare the properties of a typical metal and a non metal on the basis of the following:

     (a)Electronic configuration        (b) Nature of the oxides                

     (c) Oxidising or Reducing action     (d) Conductivity of heat and electricity.

12.  In order of obtain 1 ton of aluminium, the following inputs are required: 4 tons of bauxite, 150 kg of NaOH and 600 kg of graphite. The aluminium compound in bauxite is aluminium oxide and the main impurity is iron(III)oxide. Aluminium is obtained by the electrolysis of aluminium oxide dissolved in cryolite

     (a)When bauxite is treated with NaOH solution, state what happens to (i) Al2O3 (ii) Fe2O3

     (b)   i. Name the process used for the purification of bauxite.

     ii. Write the balanced chemical equation for the action of  heat on aluminium hydroxide.

     (c)i. Write the formula of cryolite.

     ii. Choose the correct word to complete the following sentence: By dissolving aluminium oxide in cryolite, a ____________________ (conducting/non-conducting) solution is produced.

     iii. Why is graphite required in a large quantity for the electrolytic process?

     iv. Write the balanced chemical equations for the reaction which takes place at the cathode.

     (d)   In construction work, why is an alloy of aluminum (duralumin), rather than pure aluminum, used?

13.  Zinc is extracted from zinc blende. Zinc blende is first roasted. The solid product obtained is mixed with coke in a blast furnace, from which zinc vapour emerges.

     a.   What is the zinc compound in the zinc blende?

     b.  Write the balanced chemical equation for the roasting of zinc blende.

     c.   What is the purpose of using coke?

     d.  What is the reducing agent in this extraction?

     e.   How are zinc vapours condensed to liquid?

14.  (a) From the meals Cu, Fe, Mg, Na and Zn select a different metal in each case which:                             

      i. does not react with dilute HCl.         

     Ii. Can form +2 and +3 ions.                                                 

     Iii. Has a hydroxide that reacts with both acids and alkalies.   

     Iv. Does not react with cold water but reacts with steam when heated.

     (b)   Arrange the metals of 14(a) in decreasing order of reactivity.

15.  (a)With reference to reduction of Copper oxide, Iron (II)oxide, Lead(II)oxide and Magnesium oxide by hydrogen, place the oxides in the order of increasing ease of reduction. That is, put first the oxide that is most difficult to reduce, and last, the oxide that is most easily reduced

     (b)   Write the balanced chemical equations for the following reactions;

     i.                Reduction of Copper oxide by Hydrogen.

     ii.              Reduction of Iron(III) oxide by Carbon monoxide.

     iii.            Reduction of lead (II) oxide by Carbon.

     (c)i. What is the type of bonding expected in metallic chloride?

     ii. If fused metallic chloride is electrolysed, at which electrode would metal be obtained?

     iii.What metallic property is shown by the non-metal Graphite?

     (d)   i. Cast iron contains about 4% C. By what chemical process is the amount of Carbon decreased to make steel?

     ii. Which metal is added to steel to make stainless steel?

16.  (a) What is the zinc compound obtained by roasting zinc blende?

      (c)What is the type of reaction carried out after roasting in order to obtain zinc?

     (d)   Are liquid zinc and liquid lead miscible or immiscible?

     (e)What is the name of the alloy formed between zinc and copper?

17.  ‘X’ is an element in the form of a powder. ‘X’ burns in oxygen and the product is soluble in water. The solution is tested with litmus. Write down the words which will correctly complete each of the following sentences:       

     a.   If ‘X’ is a metal, then the neutral litmus solution will turn____

     b.  If ‘X’ is a non metal, then the neutral litmus solution will turn __

     c.   If ‘X’ is a reactive metal, then _________________ gas will be evolved when ‘X’ reacts with dilute sulphuric acid.

     d.  If ‘X’ is a non metal, it will not conduct electricity, unless it is carbon in the form of _______

     e.   If ‘X’ is metal, it will form _____________ oxide, which will form _____________ solution with water.