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Environmental Chemistry Complete Notes..

Environmental Chemistry Environmental chemistry: It is the branch of chemistry that deals with the study of various chemical processes taking place in the various segments of the environment. Broadly speaking, it is the study of the sources, transportation, reactions, effects and the ultimate of the chemical species occurring in one or more segments of the environment. Components of Environment : Atmosphere:   This comprises a blanket of gaseous layer around earth. Hydrosphere :  This comprises about 96% of earth’s surface & includes all   sources of water like oceans rivers lakes, glaciers, ground water etc. Lithosphere :  It refers to earth’s solid crust containing the outer mineral cover. It comprises soil, minerals, organic matter etc.  Biosphere:   It refers to the domain of living organism in covalent with atmosphere hydrosphere as well as lithosphere.    Environmental pollution...
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CLASSIFICATION OF ELEMENTS AND PERIODICITY OF PROPERTIES Test questions Set 01




CHEMISTRY - XI

(CLASSIFICATION OF ELEMENTS AND PERIODICITY OF PROPERTIES)

Full Marks 35                                                                                                  Time: 1:15 hr                       

MULTIPLE CHOICE QUESTIONS:                                                                        1X5=5

1. Which of the following sets gives the correct order of atomic radius ?
(a) B<Al<Mg<Ca               (b) Al<B<Ca<Mg         (c) Mg<Al<B<Ca    (d) Ca<Mg<Al<B

2. Among the isoelectronic species K+, S2- ,Cl- and Ca2+ , the radii of ions decrease as :
(a) Ca2+>K+>Cl->S2-  (b) Cl->S2->K+>Ca2+  (c) S2->Cl->K+>Ca2+  (d) K+>Ca2+>S2->Cl-

3. Which of the following represents the correct order of ionization enthalpy ?
(a) F<Cl<Br<I            (b) Te<Se<S<O         (c) Na<K<Rb<Cs         (d) Si<Al<Mg<Na

4. Which among the following has the highest value of negative electron-gain enthalpy ?
(a) Ne                     (b) N                       (c) O                       (d) F

5. Which among the following is most ionic ?
(a) CCl4                        (b) SiCl4                             (c) PbCl4                         (d) PbCl2


VERY SHORT ANSWER TYPE QUESTIONS:                                                    1X5=5

6. State modern periodic law ?

7. What is meant by covalent radius of an atom ?

8. What do you mean by isoelectronic species ?

9. What is meant by electronegativity of an element ?

10. The electronic configuration of an element is 1S2 2S2 2P6 3S2 3P5 . Name the period and the group to which it belongs ?


SHORT  ANSWER TYPE QUESTIONS:                                                          2X5=10


11. The electron-gain enthalpy of O is less negative than that of S Justify ?

12. Write the provisional IUPAC names of the elements with atomic numbers 115 to 124.

13. Would you expect the second electron gain enthalpy of O as positive , more negative or less negative than the first ? justify your answer.

14. What do you mean by diagonal relationship ?

15. Explain the following :
(i) Radius of cation is less than that of the atom.
(ii) Radius of anion is more than that of the atom.


LONG ANSWER TYPE QUESTIONS:                                                           3X5=15


16. Define ionization enthalpy. Name the factors which influence its value.

17. What are the major difference between metals and non-metals?

18. What is basic difference between the terms electron gain enthalpy and electronegativity ?

 19. Arrange the elements N,P,O and S in the order of
(i) increasing first ionisation enthalpy.
(ii) increasing non-metallic character.
(iii) Trends in electron gain enthalpy.
Give reason for the arrangment assigned.

20. The first and second ionization enthalpies(KJ mol-1) of a few elements designated by Roman numerals are shown below.
              first ionization enthalpy                                        second ionization enthalpy
I                               2372                                                                                       5251
II                              520                                                                                         7300
III                             900                                                                                         1760
IV                             1680                                                                                       3380

 Which of the following element is likely to be :
(i) a reactive element          (ii) a reactive non-metal    (iii) a noble gas    (iv) a metal A that forms a stable binary halide of the formula AX2 (X = halogen) ?        


By:Anjani Kumar Singh       


Comments

  1. Unknown18 March 2018 at 22:49

    Thanks sir I really enjoyed to solve this paper...
    But I have a doubt in the question no. 1....
    I know it really sounds ridiculous, but I'm unable to solve that one...
    So please give me the answer of question no. 1 with justification...

    ReplyDelete
    Replies
    1. Unknown19 March 2018 at 00:34

      Ans. 1 (a) boron is a 2nd period element so is size is smaller while calcium is 4th period element so it's size is larger among all elements.
      In case of Al and Mg the size of Al is smaller due to high effective nuclear charge.

      Delete

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