CHM 101 PAST QUESTIONS

CHM 101 PAST QUESTIONS


 CHM101 - Introductory Inorganic Chemistry 



Organic compounds can be obtained from __________ and can also be made synthetically in the laboratory. ANS=NATURAL SOURCES 

2.________ organic chemistry involves the determination of organic compounds. ANS=QUALITATIVE 

3.The most obvious method of using a balance is known as________? ANS=DIRECT WEIGHING

4.__________system not only measure total mass but also may determine such characteristics as average weight and moisture content? ANS=ELECTRONIC WEIGHING

5.Balances in the sortorius 2400 series allow one to determine weight (mass) to within___________? ANS=0.0001g 

6.List the tree types of balances known to you and state the range of their measurements?? 

7.The use of large flame during heating my lead to______? 

8.A substance that does not burn in flame is probably a_____? 

9._________are those in which a substance,usually a solid, is weighed. ANS=GRAVIMETRIC PROCEDURES. 

10.When isolation of a pure solid is difficult,or rapid filtration is necessary,_______is employed?? ANS=VACUUM FILTERATION. 

11.A________is a small machine (with several test tube holder)that rotates rapidly. ANS=centrifuge 

12.Before a ------ is turn on a test tube must be placed opposite the test tube of interest to prevent excessive vibration ANS=CENTRIFUGE 

13.___________is a technique employed to purify an organic solid that may be contaminated by impurities. ANS=RECRYSTALLIZATION 

14.__________of most organic compounds in common solvent increases as the temperature is increases? ANS=SOLUBILITIES 

15.dissolution are generally endothermic process.YES\NO ANS=YES 

16.What are the two conditions for selecting a desired solvent for recrystallization?? ANS=a.the solubility of the desired substances in the solvent at high temperature and b.the solubility of the impurity in the solvent at lower temperature. b.the solvent should not react chemically with the desired substance.

17.___________is a useful method for purification and isolation, but it is restricted to solids, and it is a relatively inefficient way to separate a mixture of very similar compounds. ANS=CRYSTALLIZATION 

18.___________is the general term for the recovery of a substance from a mixture by bringing it into contact with a solvent that preferentially dissolves the desired material. ANS=EXTRACTION 

19.The process of extraction is concerned with the_______?? ANS=DISTRIBUTION LAW OR PARTITION LAW 

20.___________prevent a sharp boundary between layers? ANS=EMULSIONS

21.All methods of separations depends on_________? 

22._______prevent a sharp boundary between two immiscible solvent layers in a separating funnel ANS=EMULSIONS 

23.Those properties that substances exhibit without undergoing a change in chemical composition are______? ANS=PHYSICAL PROPERTIES

24._________ are those that substances can exhibit only when undergoing a change in chemical composition? ANS=CHEMICAL PROPERTIES 

25.The temperature at which the liquid and the solid state of a substance are in equilibrum is called________? ANS=MELTING POINT 

26.during melting point determination,it is advisable to__________? ANS=CALIBRATE THE THERMOMETER 

27.The temperature at which the vapour pressure equals the applied pressure is__________? ANS=BOILING POINT. 

28.The density of a substance varies with______? ANS=TEMPERATURE 

29.Most pure substance have_________melting point? ANS=SHARP

   


Past Questions: CHM101 - Introductory Inorganic Chemistry COURSE 

TITLE: INTRODUCTORY INORGANIC CHEMISTRY ___CHM 101 (75+ POSSIBLE QUESTIONS AND ANSWERS BY DGREATPROF) 

 1 : The ability of an element to participate in a chemical reaction is measured in form of its --------- Ans - ionization energy 

2 : Electron affinity can be affected by all but one of the following Ans - mass number

3 : In the mordern form of Mendeleev peroidic table, elements are arranged in --------horizontal rows. Ans - 7 

4 : _________ used the Law of the Octave to arrange atoms Ans - John Newlands 

5 : _____states that as far as possible in a given atom in the ground state, electrons in the same sub shell will occupy different orbitals and will have parallel spins. Ans - Hund's rule 

6 : __________ arranged elements in order of increasing atomic weight on a line which spiraled around a cylinder from bottom to top Ans - De Chanourtios 

7 : Halogens have ------ electron affinity Ans - exothermic

8 : ________and____________ tried to classify elements into periods Ans- De Chancourtois and Dobereiner 

9 : An orbital can have at the most two electrons of opposite spin can be called the ------- Ans - Exclusion principle 

10 : Increase in principal quantum number(n) means-----of the atomic radii Ans - increase 

11 : The alkali metals belong to the ------ elements Ans - s-block 

12 : The second ionization energy of alkaline earth metals is less than that of corresponding alkali metals because-------- Ans - of stability of a closed shell configuration

13 : ____is the energy released or absorbed when an electron is added to the gaseous atom in its ground state Ans - electron affinity 

14 : The properties of elements are periodic functions of their atomic numbers is the----------- Ans - Mordern periodic law 

15 : ____________is the enthalpy change when one mole of crystal lattice is formed from the isolated gaseous ions Ans - lattice energy

16 : _________is the tendency of an atom to attract towards itself the shared electron pair of a bond in which it is involved Ans - electronegativity 

17 : What property was used by Mendeleev to classify the elements? Ans - chemical properties 

18 : In the equation for ionization,effective nuclear charge is represented as------ Ans - Z 

19 : Which is of these peroids of the peroidic table has only eight elements? Ans - 3

20 : The positions of K and Ar,Co and Ni do not remain anomalous any longer since --------- is used in arranging the elements. Ans - atomic number 

21 : Arrange the following metals in an increasing order of their boiling point LI,Cs,Rb,K Ans - Cs,K,Rb,Li

22 : Arrange the following alkali metals in order of their atomic number,Na,K,Li, Ans - Li,Na,K 

23 : According to,electronegativity is equated to the force of attraction between an atom and the electron seperated by a distance equal to the covalent radius of the atom. Ans- AlfredRochow 

24: Which of these metals can their compounds be used in photography ? Ans - K 

25 : All these are types of metal lattices except Ans - hexagonal 

26 : Which of these statements is not true of metallic elements? Ans - They form acidic oxides

27 : __________is a requirement in the electrolysis of beryllium chloride Ans - Sodium Chloride

28 : In the extraction of calcium from fused calcium chloride,is used as the anode Ans - graphite

29 : All these are uses of Beryllium except Ans - used for making aircraft 

30 : Calcuim oxide is a constituent of all but one of the following Ans - barium 

31 : On exposure to air alkaline earth metals lose their silvery luster because Ans - a layer of oxide is formed on their surface

32 : All the alkaline earth metals form ionic compounds except Ans- beryllium 

33 : Calcium compounds give out a characteristic flame colouration Ans - brick red 

34 : The hydrogen energies of alkaline earth metal ions are much greater than those of alkali metals because Ans - they are smaller with increased cationic charge 

35 : Which of these statements is not true of alkaline earth metals? Ans -They are less dense than alkali metals 

36 : The first ionization energy of alkaline earth metals is more than that of corresponding alkali metals because Ans - the alkaline earth metals have higher nuclear charge and are smaller in size 

37 : ___________ is extremely rare and it is a radioactive element Ans - raduim 

38 : ___________ is the second most abundant metallic element in sea water Ans - magnesuim 

39 : Which of these statements is not true of lithium? Ans - Lithium reacts spontaneously with water 

40 : The strong cohesive forces present in the lithium atom gives rise to all but one of the following Ans - softness 

41 : Hydrides of alkali metals react with water to librate which of these?______________ Ans - hydrogen 

42 : Which of these alkalis has the most stable floride?______________ Ans- lithium 

43 : Why was Newlands law of octaves rejected?____________ Ans - It could not hold good for elements heavier than calcium 

44: Which of these statements is not true of metallic hydrides? ______________ Ans - they are volatile 

45 : Which property was used by Mendeleev to classify elements?_______________ Ans - chemical properties 

46 : Which of these alkali metals is the most electropositive?_____________________ Ans - caesuim 

47 : The presence of hydrogen bond in most molecules is responsible for the following EXCEPT __________. Ans – Low boiling point 

48 : The tendency of an atom to attract towards itself shared electron pair of a bond is known as _________. Ans – Electronegativity 

49 : Which of the isotopes of hydrogen is radioactive?________________ Ans – Tritium 

50 : All these can be used as raw materials for the production of oxygen except _________. Ans – Nitrogen 

51 : Which of these is not a covalent hydride?___________________ Ans - NaH 

52 : The most abundant metal in sea water is called ______. Ans – Sodium 

53 : Which of these statements is not true of metallic elements?_____________ Ans - They form acidic oxides 

54 Which of the following is not true as we move down a group of s and pblock elements in the periodic table? _______________ Ans - Electronegativity also increases 

55 Stability of alkali salts depends on which of the following?__________ Ans - enthalpy of formation of the salt 

56 : How many electrons are in potassium atom?__________ Ans - 19 

57 How many elements are there in period 6 of the periodic table ? ______ Ans - 32 

58 : Which of these elements behave partly as the alkaline metals as well as a halogen element? ____________ Ans – Hydrogen 

59 : Which of these periods of the peroidic table has only eight elements? ____________ Ans - 3 

60 : Which of these elements has the electronic configuration of 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{1}? Ans – Cu 

61 : In the periodic table,period 6 contains elements Ans – 32 

62 : Which of these is not an isotope of hydrogen? Ans – Neutrium 

63 : __________ forms an oxide also known as heavy water. Ans – Deutrium 

64 : Which of the isotopes of hydrogen is radioactive? Ans – Tritium 

65 : All these can be used as raw materials for the production of oxygen except Ans – Nitrogen 

66: Hydrogen can be obtained economically as a biproduct in the electrolysis of Ans – brine 

67 : Which if these is not a property of hydrogen? Ans - it has a pungent smell 

68 : Hydrogen may be used for all but one of the following. Ans - synthesis of zinc 

69 : Hydrogen may not be advantagous as a fuel becauseAns - it is a secondary source of energy 

70 ______types of hydride compounds can be formed depending on the electronegativity of the elements Ans -3 

71 : When alkali metals are heated with hydrogen they formhydrides Ans – ionic 

72 : Silt is an example of hydride Ans - Covalent 

73 : Which of these statements is not true metallic hydrides? Ans - they are volatile 

74 : Sodium Hydride is an example of hydride Ans – ionic 

75 : Which of these statements is not true of metallic elements? Ans - They form acidic oxides 

76 : All these are consequences of the sole valence electron in alkali metals except Ans - the metals are soft 

77 : Which of these statements is not true? Ans - All metals react with carbon to form carbides 

78 : In the group of the alkali metals the degree of hydrationdown the group. Ans – decreases  

Note the following: Lecoq de Boisbaudran called the element gallium and said its density was 4.7x103. Mendeleev on hearing this wrote to Lecoq de Boisbaudran telling him that everything he said about the new element was correct except its density. On further position of the metal, Lecoq de Biosbaudran discovered that Mendeleev was right that the density of gallium was 5.8 x103 kg just like it had been predicted by Mendeleev.  Further proof of the law came via the works of Lars Fredrick Nilson who discovered scandium and Winkler who discovered germanium. Both elements were found to have properties corresponding to those of earlier predicted for them by Mendeleev.

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