PRACTICE PAPER-6

ICSE PRACTICE PAPER-6
PERIODIC TABLE, CHEMICAL BONDING, PRACTICAL CHEMISTRY and  METALLURGY

                                                            SECTION I (40 Marks)

                                                Attempt all questions from this section.

Question 1

a) Name the following compounds:

            i) CaCl₂

           ii) MgO

          iii) ZnSO₄ 

          iv) NH₄Cl

           v) (NH₄)₂SO₄

b) What would you observe in each of the following cases:-

i)  Sulphur dioxide gas passed through potassium dichromate solution.

ii)  Chlorine gas is tested with  moist starch iodide paper.

iii) .Hydrogen sulphide gas is tested with  lead acetate paper.

iv) Reaction of silver nitrate  solution with hydrogen chloride gas.

v) Ammonia gas is passed through Nesslers reagent.

c) Complete and balance the following reactions:-

i)   Fe + H₂O

ii)  Zn + HCl →.

iii) N₂ + H₂ →.

iv) Mg + H₂O→

v)  C + H₂O→

d) Give reasons:-

i)   Electron affinity of noble gases is zero.

ii)  Fluorine is the most electronegative element of the periodic table .

iii) Atomic size decreases across the period.

iv) Atoms with large atomic size shows low ionization potential.

v)  Electron affinity is highest for halogens.

e) Match column-I with column-II as shown in the example given below:-

          (vi) - (A) 

                COLUMN-I                                           COLUMN-II

(i)     O₂                                          (A) A covalent compound with triple bond.

(ii)   NH₃                            (B) A non polar covalent compound.

(iii)  Cl₂                              (C) A covalent Molecule with single bond.       

(iv)  CH₄                            (D) A covalent compound with one lone pair of electrons on                              only one atom

(v)   AlCl₃                           (E) A covalent compound with double bond.

(vi)  N₂                                         (F) An ionic compound.

f) For part (i) to (x), select the correct answer from choices A, B, C and D which are given.

        Write only the letter corresponding to the correct answer.

   (i) Number of electrons in the valency shell of metals.

          A.   1,2or3                                              B.   3,4or5

          C.   2,3or4                                              D.  4,5,6or7.

   (ii) Number of electrons in the valency shell of non metals :

          A. 1,2or3                                                B.   3,4or5

          C.   2,3or4                                              D.  4,5,6or7

   (iii) A weakly electropositive metal :-

          A.Sodium                                              B. Magnesium

          C.Potassium                                          D.Aluminium.

   (iv) A metal which belongs to Alkali metals:-

          A. Copper.          B. Zinc          C.  Sodium  .D. Tungsten

  

 (v) A monovalent metal :

           A. Calcium                                        B. Copper

           C. Sodium                                         D.Zinc 

   (vi) Identify  highly electronegative element from following:

            A.  Fluorine                                      B. Chlorine

            C.  Potassium                                   D.  Sodium

   (vii) A gas released when active metals react with acids:

            A. Hydrogen                                    B. Nitric oxide

            C. Nitrogen                                      D.Carbondioxide 

   (viii) Number of valency electrons in Alkali metals:-

              A.5                                                  B. 2

              C. 1                                                 D. 4

   (ix)  A metal which belongs to Alkaline Earth metals:

              A.  Cu                                              B.  Sn

              C.  Mg                                             D.  Fe

    (x)An amphoteric metal:-

               A.  Na                                            B.   Mg

               C.  K                                                         D.   Pb 

g) Find the odd one out in each case:-

(i)     A.AlCl₃                      B. NaCl                  C. CH₄                D. MgCl₂

(ii)   A. Ba                          B. Na⁺                    C.  Ca                  D.Mg

(iii) A. Al₂O₃                            B. CaO                        C. K₂O                D. SO₂

(iv) A. Na                                   B. Mg                    C. N₂                             D.Ca.

(v)   A.CH₄                           B. N₂                   C. Cl₂                            D. H₂

                                     SECTION-II(Attempt any four)

Question-2.                                                                                                     [3+3+2+2]

  a)    (i) Why do all ionic compounds have high melting and boiling points?

         (ii) Draw the structure of  an ammonium ion

         (iii) Name the bond/bonds present in the structure of ammonium

  

  b)  Choose from the list of elements given below:-

          (A)   Argon     (B) Aluminium      (C) Oxygen       (D) Nitrogen

      1. Contains a triple covalent bond              2. Exists in diatomic and triatomic state.

      3. Is monoatomic                                          

  c) Draw orbital structure for MgCl₂

  d) Differentiate between polar and non polar covalent bonds.

Question -3.                                                                                                               [4+2+2+2]

           a) An element ‘X’ has E.C. 2,8,8,2 without identifying ‘X’, answer the following:-

         (i) Predict charge on ‘X’

        (ii) State whether it is a metal or nom-metal

        (iii)What formula do you expect the chloride of ‘X’ to have?

        (iv) Type of bond in  the compound formed in (iii)

    b) Differentiate between electron affinity  and electronegativity.

    c) Name the following:-

         (i) Metalloid in period 3

        (ii) Element in group15 and period 3

   d) Arrange the following as per the instructions:-

               (i)Br, F, Cl (Increasing electronegativity)   (ii)Na, K, Li (Decreasing atomic radii)

Question -4.                                                                                                               [5+2+3]

a) Identify A-E from the options given below:-

    ( Potasssium iodide paper, lead acetate paper, Moist blue litmus, moist starch iodide                        paper, Alkaline pyrogallol)

i)    A gas with rotten egg smell  changes A to silvery black.

ii)   A reddish brown coloured gas  which turns B to brown.

iii)  A colourless neutral gas which turns C to brown.

iv)  A Greenish yellow coloured gas which turns D to blue black.

v)   A colourless gas which turns E to faint red.

b) Give one chemical test to distinguish

     (i) SO₂ and CO_2.

      (ii) SO₂ and H₂S.

c)  Fill in the blanks with the choices given:-

     i) A gas with burning sulphur smell__________(SO₂/CO₂).

    ii) A gas with pungent odour__________(NH₃/ CO₂).

   iii) A reddish brown coloured gas________( SO₂/NO₂).

Question -5.                                                                                                               [4+3+3]

a) Draw electron dot and orbital structures for following compounds:-

     i) NaCl                     ii) MgO      

b) Compound X consists of molecules, answer the following:-

     i) Type of bonding in X.

    ii) Is it a conductor or non conductor?

   iii) State its physical state.

c)  i) What is lone pair of electrons.

     ii) Show electron dot diagram for formation of oxygen molecule.

    iii) Number of lone pair of electrons on oxygen atom in water molecule.

Question- 6                                                                                             [5+2+3]

          a) Balance the following reactions:

 i) Pb(NO₃)₂  à PbO+ NO₂ + O₂

ii) Cu + HNO₃ à Cu(NO₃)₂+ H₂O +NO₂

iii)  NH₃+ O₂ à NO + H₂O

iv) HCl à Cl₂ + H₂

v) Zn + HClà ZnCl₂ + H_2.

        b) Give the formulae of following compounds:-

          i) Ammonium phosphate.

         ii) Sodium bicarbonate.

      c) Name the following Radicals/ions.

         i) CO₃^2-           ii) Fe³⁺               iii) PO₄^3-

Question- 7                                                                                             [2+2+2+4]    

        a) State your observation:-

       i) Reaction of Sodium with water.

b) Account for the following facts:-

            i) Though lead is above the hydrogen in the activity series, it does not react with dilute                     hydrocholoric acid or dilute sulphuric acid.

           ii) Potassium and sodium are not used to react with with dilute hydrocholoric acid or                       dilute sulphuric acid in the laboratory preparation of hydrogen.

    c)  State why hydrogen is not prepared in the laboratory by the action of –

i) Sodium with cold water.

ii) Calcium with dilute sulphuric acid.

    d) Fill in the blanks with reference to group 1 with correct option from given:-

i)  The elements are_________(Light/ Heavy)_________(Metals/Non-metals) since                         their atomic size is __________(Large/Small).The energy binding the atoms is                   ________(High/Low) hence the elements have_________(High/Low)Melting points.