Class - IX Chemistry (Subjective) Model Question-10

Class - IX

Subject : Chemistry (Subjective)

Time :  2 hrs.                                                                                                                            Marks. 40

Section A : (any five)

1.         Write down the differences betⁿ physical and chemical changes.                                                             2

2.         What are homogeneous and heterogeneous mixture ?                                                                2

3.         Show the classification of matter.                                                                                                           2

4.         What is valency ? Explain with examples.                                                                                              2

5.         What is radical ? Explain with examples.                                                                                                2

6.         Write down the structural formula of hydrazoic acid and nitric acid.                                            2

7.         What is mass number and atomic number ?                                                                                           2

8.         How many isotopes hydrogen has ? Write their names.                                                              2

9.         Write down the electronic configuration of K (19) and Ne (10).                                                 2

10.       Name the inert gases.                                                                                                                2

Section B : (any five )

11.       a)         What is ionic bond ? How is an ionic bond formed, Explain with Na Cl.                         1+3

            b)         What is metallis bond ?                                                                                                             2

           

12.       a)         Write down the properties of ionic bond .                                                                                  3

            b)         What kind of a compound is Ca Cl₂ ? Justify.                                                                            2

            c)         What is an ion ?                                                                                                                        1

13.       a)         What are fundamental particles ? Describe three most important fundamental particles. 1+3

            b)         Define active and dormant valency.                                                                                           2

14.       a)         Write down the differences between emprical formula and molecular formula.                4

            b)         Define              (i)         Weight             (ii)        Mass.                                                               2

15.       a)         What is chemical equation. Explain the rules of writing chemical equations.                     1+3

            b)         What is meant by a structural formula ?                                                                                     2

16.       a)         What is covalent bond ? How is it formed ? Explain with examples.                               1+3

            b)         Covalent compounds have low melting and boiling points, why ?                                                2

           

17.       a)         Describe Rutherford's atomic model .                                                                                        4

            b)         Write down the limitations of Rutherford's atomic model.                                                           2

18.       a)         In a compound, percentage of C, H and N is 75.94%, H = 6.33% N= 17.72% respectively.

            It vapour density of compound is 39.5, then calculate molecular formula of the compound.         4

            b)         Write down the valency of the following elements or radicals.                                         2

                        i)          NH₄                             ii)         Phosphorus.

19.       a)         What is molecular formula ? Give examples.                                                                  2

            b)         What is the significance of molecular formula. Describe them.                                         2+2

           

20.       a)         Write the no. of protons, electrons and neutrons in the following atoms and ions.                        3

                        (i)         13 C                 (ii)        23 _Na+                          (iii)       ¹⁶O²-

                                      6                                11                                            8

            b)         Write down the name of the following compounds.                                                                    3

                        (i)         (NH₄)₂ SO₄                  (ii)  Fe Cl₂       (iii)               S

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