1. Work Book (Phase - I)
Subjective:
Board Type Questions
1. What is the maximum number of electrons with clockwise spin that can be
accommodated in a f subshell?
2. What is the restriction imposed on Rutherford model of an atom by Bohr’s model atom?
3. How much charge in coulombs is carried by the nucleus of an atom of oxygen?
4. Atomic number is defined in terms of protons usually and not in terms of electrons. Why?
5. For any given series in the spectrum of hydrogen, there is a wavelength limit beyond
which the spectrum becomes continuous (not discrete). Explain.
6. An electric bulb emit light discontinuously in accordance with Planck’s quantum theory,
but it appears to us as if light is being emitted continuously. Explain.
7. What is the shape of H3O+ ion? Explain your answer.
8. Is CaF2 linear or bent or neither of the two? Justify.
9. Out of NaCl and MgO, which has higher lattice energy and why?
10. Why NaCl gives a white precipitate with AgNO3 but CCl4 does not?
11. Arrange the following in order of decreasing bond angles:
CH3, NH3, H2O, BF3, C2H2
12. Why NF3 is pyramidal but BF3 is triangular planar?
13. IE2 for alkali metals shows a jump whereas IE3 for alkaline earth metals shows a jump.
Explain.
14. The electron affinity of nitrogen is lower than that of carbon. Why?
15. Which main group element (s) has (have) a different number of outermost electrons than
its (their) group number?
16. How is the electron affinity of a positive ion related to its ionization potential?
17. Does an element have a negative ionization potential?
18. Explain, strong electropositive elements are good reducing agents.
19. Potassium bromide contains 32.9% by weight of potassium. If 3.20 g of bromine reacts
with 3.60 g of potassium, calculate the number of moles of potassium which combine with
bromine to form KBr.
20. 9.7  1017 atoms of iron weigh as much as 1cc of H2 at STP. What is the atomic mass of
iron?

2. 21. Two bulbs B1 and B2 of equal capacity contain 10 g of oxygen (O2) and ozone (O3)
respectively. Which bulb will have grater number of oxygen atom and which have greater
number of molecules?
22. Why are atomic masses of most of the elements are fractional?
23. What is meant by 1 gram atom of iron?
24. Round each of the following figures to four significant figures
(a) 12,345,670
(b) 2.35500
(c) 456,500
(d) 3.218  103
True/False
25. Isosters has different number of atoms.
26. Splitting of spectral lines in the presence of electric field is called stark effect.
27. The sp2 hybrid orbitals have equal s and p character.
28. The overlap of p – orbitals always leads to the formation of a  bond.
29. The increasing order of electron affinity of F, Cl and Br is F < Cl < Br
30. The ionic radius decreases with increase in nuclear charge.
31. In SI units A is the symbol for temperature on absolute scale.
32. Temperature in the Kelvin scale does not use the degree sign because it is an absolute
scale and not a relative scale.
Fill in the Blanks
33. The mass of an atom M and its ion M2+ is…………………….
34. The orbital angular momentum of an electron in 2s orbital is ……………….
35. Each molecular orbital whether bonding or antibonding can accommodate a maximum
of…………………..electrons.
36. The bond order of He2
+ is…………………….
37. Ca2+ ion has smaller radius than K+ ion because Ca2+ has……………….
38. The first ionization potential of nitrogen is……………than that of oxygen.
39. The weight of 1  1022 molecules of CuSO4.5H2O is…………………..
40. A pure substance that contains only one kind of atoms is called……………..
IIT Level Questions
41. The nucleus of an atom can be assumed to be spherical. The radius of nucleus of an
atom is given by 1.25  101
 A1/3 cm where A is the mass number of nucleus. Radius of
the atom is 1
o
A . If the mass number is 64, what is the fraction of the atomic volume that
is occupied by the nucleus?

3. 42. Show that if the uncertainty in the position of a moving electrons is equal to its de-Broglie
wavelength, then its velocity is completely uncertain.
43. The electron energy of hydrogen atom in the ground state works out to be
2.18  1018
J per atom. Calculate what will happen to the position of the electrons in
this atom if the energy of 1.938  1018
J is applied to each hydrogen atom.
44. At room temperature, NO2 gas is paramagnetic in nature. When its is cooled below 0C it
acquires diamagnetic behaviour. Explain this observation on the basis of structure?
45. Explain why 2
ClF
is linear but 2
ClF
is a bent molecular ion?
46. First and second ionization energies of Mg(g) are 740 and 1450 kJ mol1
. Calculate
percentage of Mg+ (g) and Mg2+(g), if 1 g of Mg(g) absorbs 50 kJ of energy.
47. Select paramagnetic and diamagnetic species among the following:
2 3 2 3
Na , Cl , Sn , Co , Cd, Zn , Cr
     
48. If 12.6 g of NaHCO3 is added to 20.0 g of HCl solution, the residue solution is found to
weigh 24.0 g. What is the mass and volume of CO2 released at NTP in the reaction?
49. 1 g of a metal, having no variable velency, produces 1.67 g of its oxide when heated in
air. Its carbonate contains 28.57% of the metal. How much oxide will be obtained by
heating 1 g of the carbonate?
50. Two oxides of a metal contain 63.2% and 69.62% of the metal. The specific heat of the
metal is 0.117. What is the formula of the two oxides?

4. Objective:
Multiple choice questions with single correct options
1. Which of the following is smallest in size?
(A) 3-
N (B) 2-
O
(C) -
F (D) Na+
2. Which of the following transition of electron in H – atom will emit maximum energy?
(A) 

5 4
n n (B) 

4 3
n n
(C) 

3 2
n n (D) All will emit same energy
3. Cathode rays can be deflected by
(A) magnetic field only (B) electric field only
(C) both type of fields (D) none of these
4. When the speed of electron increases, the specific charge
(A) increases (B) decreases
(C) remain same (D) none of these
5. Which of the following is not characteristic of X – rays?
(A) Can ionise the gas
(B) Cause ZnS to fluorescence
(C) Deflected electrical and magnetic field
(D) Have wave length shorter than UV rays
6. If each H – atom is excited by giving 8.4 eV of energy, then number of spectral lines
emitted is equal to
(A) One (B) Two
(C) Three (D) None
7. Calculate the radius of a nucleus of an atom of mass number 216. Given

  13
o
R 1.4 10 cm
(A) 8.4 Fermi (B) 4.8 Fermi
(C) 7.8 Fermi (D) 10.2 Fermi
8. In Rutherford’s scattering
 experiment thin foil of gold was used because gold is
(A) ductile (B) malleable
(C) cheap (D) not a coinage metal
9. The uncertainty in the position of an electron if it is moving with a velocity of

 4 1
3 10 cm s accurate upto 0.011% will be
(A) 1.92 cm (B) 7.68 cm
(C) 0.175 cm (D) 3.84 cm
10. Potential energy of Li2+ electron is
(A)
 2
0
3 e
4 r
 
(B)
2
0
3 e
4 r
 
(C)
 2
2
0
2 e
4 r
 
(D)
 2
0
e
4 r
 
11. Which one of the following ion has bond order value other than 2.5?
(A) 2
O
(B) 2
O
(C) 2
N
(D) 2
N

5. 12. In 3
4
PO 
ion, the formal charge on each oxygen atom and PO bond order respectively
are
(A) 0.75, 1.25 (B) 3, 1.25
(C) 0.75, 1.0 (D) 0.75, 0.6
13. Which of the following is most polar?
(A) CO (B) CF
(C) OF (D) NF
14. The structure of ICl2

is
(A) trigonal (B) trigonal bipyramidal
(C) octahedral (D) square planar
15. Which has net dipole moment?
(A) BF3 (B) CCl4
(C) BeF2 (D) SO2
16. Which force is strongest?
(A) dipole-dipole (B) ion-ion
(C) ion-dipole (D) ion-induced dipole
17. As the s-character of hybridized orbital increases, the bond angle
(A) increases (B) decreases
(C) does not change (D) none of the above
18. The bonds between P atom and Cl atoms in PCl5 are likely to be
(A) ionic with non covalent character
(B) covalent with some ionic character
C) covalent with no ionic character
(D) ionic with some metallic character
19. Which of the following species has 4 lone pairs of electrons in its outermost shell?
(A) I (B) O
(C) Cl
(D) He
20. The compound in which carbon uses its sp3 hybrid orbitals for bond formation is
(A) HCOOH (B) NH2CONH2
(C) HCOH (D) CH3CH2OH
21. Which following set contains pair of elements that do not belong to same group but show
chemical resemblance?
(A) Hf, Zr (B) K, Rb
(C) Be, Al (D) B, Al
22. The I. E. of Al is smaller than that of Mg because
(A) atomic size of Al > Mg.
(B) atomic size of Al < Mg.
(C) I. E. in Al pertains to the removal of p-electron which is relatively easy.
(D) unpredictable.
23. From the ground state electronic configurations of the elements given below, pick up the
one with highest value of second ionization energies
(A) 1s2, 2s2, 2p6, 3s2 (B) 1s2, 2s2, 2p6, 3s1
(C) 1s2, 2s2, 2p6 (D) 1s2, 2s2, 2p5

6. 24. r(van der Waal) is
(A) half the bond length
(B) twice the bond length
(C) half the distance between centres of nuclei of two non-bonded atoms of adjacent
molecules in solid state
(D) none of the above
25. The correct arrangement of O, P and N in order of increasing radii is
(A) O < N < P (B) P < O < N
(C) O < P < N (D) N < O < P
26. Which of the following represents the incorrect order of ionic radii?
(A) Al3+ < Mg2+ < Na+ (B) Na+ < Mg+ < Al+
(C) Br– < Cl– < F– (D) Br
> Cl
> F
27. In which of the following binary compound the ratio, rcation/ranion is least?
(A) LiI (B) CsI
(C) LiF (D) CsF
28. Which of the following does not have any unit?
(A) Electronegativity (B) Electron affinity
(C) Ionization potential (D) Atomic radii
29. Which of the following oxide is most acidic?
(A) Na2O (B) Al2O3
(C) P2O5 (D) SO3
30. A sudden large jump between the values of second and third ionization energies of an
element would be associated with which of the following electronic configuration?
(A) 1s2, 2s2, 2p6, 3s1 (B) 1s2, 2s2, 2p6, 3s2, 3p1
(C) 1s2, 2s2, 2p6, 3s2, 3p6 (D) 1s2, 2s2, 2p6, 3s2
31. The volume of a gas at STP is 
 7
1.12 10 ml. Calculate the number of molecules
present in the gas
(A)  16
6.692 10 (B)  12
3.01 10
(C)  13
3.01 10 (D)  10
3.01 10
32. The number of molecules in 100 ml each of O2, NH3 and CO2 at STP are
(A) NH3 > O2 > CO2 (B) NH3 < CO2 < O2
(C) NH3 < O2 < CO2 (D) The same
33. Haemoglobin contains 0.33% iron by weight. The molecular weight of haemoglobin is
67.200. Calculate the number of gram–atoms of iron per molecule of haemoglobin
(Fe = 56).
(A) 0.2 gram–atoms of Fe (B) 0.4 gram–atoms of Fe
(C) 4 gram–atoms of Fe (D) 2 gram–atoms of Fe
34. Calculate the weight of BaCl2 needed for complete precipitation of BaSO4 from 30.5 ml of
0.1 M H2SO4 (Ba = 137.32).
(A) 0.635 g (B) 0.032 g
(C) 3.2 g (D) 0.42 g
35. Which of the following does not depend on temperature?
(A) Molality (B) Mole fraction
(C) Mole (D) All of the above

7. 36. A solution contains ethanol and water. The mole fractions of ethanol and water in the
solutions are
1 4
and
5 5
respectively. The ratio of mole percentage of ethanol water is
(A) 0.50 (B) 0.25
(C) 0.80 (D) 0.20
37. What volume of a 0.8 M solution contains 100 millimoles of the solute?
(A) 50 ml (B) 12.5 ml
(C) 125 ml (D) 250 ml
38. Which of the following samples contains the smallest number of atoms?
(A) 1 gm of CO2(g) (B) 1 g of C8H18 ( )
(C) 1 gm of LiF(s) (D) 1 g of B4H10(g)
39. Density of water at room temperature is 1g/ml. How many molecules are there in a drop
of water, if its volume is 0.05 ml?
(A) 1.67  1021 (B) 16.7  1021
(C) 6.023  1023 (D) 1.67  1023
40. The number of oxygen atoms required to combine with 14 gm of nitrogen to form N2O3
when 80% of nitrogen is converted to N2O3
(A) 3.6  1023 (B) 1.8  1023
(C) 0.36  1023 (D) 7.2  1023
Multiple choice questions with more than one option correct
41. The orbital which have lobe along the axis is/are
(A) 2
z
d (B) dxz
(C) 2 2
x y
d 
(D) dxy
42. The spectrum of He is expected to be similar to that of
(A) H (B) Li+
(C) Be2+ (D) H+
43. The energy of an electron in 2py orbital is
(A) greater than that of 2px orbital (B) less than that of 2px orbital
(C) equal to that of 2px orbital (D) equal to that of 2pz orbital
44. Which of the following is not true for Bohr’s model of atom?
(A) It explained the spectrum of H-atom
(B) It explained the spectrum of He+ ion
(C) It explained the spectrum of Li+ ion
(D) It explained the absorption spectrum only
45. If the velocity of a particle is doubled
(A) wavelength of the particle wave is halved
(B) momentum of the particle is doubled
(C) momentum remains unchanged
(D) frequency of the particle wave is doubled
46. The molecules (s) which show H – bonding is /are
(A) o–nitrophenol (B) Water
(C) HF (D) ethyl acetoacetate
47. Which possess fractional bond order?
(A) O2
+ (B) O2

(C) H2
+ (D) N2

8. 48. A, B & C are three substances. A does not conduct electricity both in the fused and
solution states, while C conducts electricity only in the solution state, B conducts
electricity both in fused and solution state. Which of the following statements (s) is / are
true regarding A, B and C?
(A) A has polar covalent linkage (B) A has non – polar covalent linkage
(C) B is ionic in nature (D) C has polar covalent linkage
49. CO2 is isostructural with
(A) HgCl2 (B) SnCl2
(C) C2H2 (D) NO2
50. Which combination (s) given below is / are correct?
(A) HgCl2 – Linear (B) CIF3 – T shaped
(C) ICl4

- square planar (D) XeF6 – pentagonal bypyramidal
51. The properties which are common to both groups 1 and 17 elements in the periodic table
are
(A) Electropositive character increases down the groups
(B) Reactivity decreases from top to bottom in these groups
(C) Atomic radii increase as the atomic number increases
(D) Electronegativity decreases on moving down a group
52. Which of the following pairs of elements have almost similar atomic radii?
(A) Zr, Hf (B) Mo, W
(C) Co, Ni (D) Nb, Ta
53. Chlorine atom does not differ from chloride ion in the number of which of the following?
(A) Electrons (B) Size
(C) Protons (D) Neutrons
54. Which of the following processes do not involve absorption of energy?
(A)    
S g e S g
 
  (B)    
2
O g e O g
  
 
(C)    
Cl g e Cl g
 
  (D)    
O g e O g
 
 
55. Which of the following show amphoteric behaviour?
(A) Zn(OH)2 (B) BeO
(C) Al2O3 (D) Pb(OH)2
56. Identify the correct statements among the following:
(A) 0.5 g-atom of oxygen contains A
N
4
oxygen molecules.
(B) 0.5 g-molecule of oxygen contains A
N
4
oxygen molecules.
(C) total electrons present in 0.5 g-atom of oxygen is 4NA.
(D) total electrons present in 0.5 g-atom of 2
O
is A
7N
4
.
57. The amount of CaO required to remove hardness of 106 litre of water containing 1.62 g of
calcium bicarbonate per litre, is
(A) 5.6 kg (B) 560 kg
(C) 104 moles (D) 560 g
58. A 100 ml solution of 0.1 M HCl was titrated with 0.2 M NaOH solution. The titration was
discontinued after adding 30 ml of NaOH solution. The titration was completed by adding
0.25 KOH solution. Hence,
(A) volume of KOH required for completing the titration is 16 ml
(B) millimoles of HCl = millimoles of NaOH + millimoles of KOH
(C) millimoles of HCl = millimoles of NaOH
(D) millimoles of HCl = millimoles of KOH

9. Match the Following
59. Match the items (or quantity) given in column – I with that of given in column – II
Column - I Column - II
(i) Isobars (a) de-Broglie
(ii) -particles (b) Bohr’s model
(iii) hydrogen spectrum (c) positively charged particles
(iv) dual nature of matter (d) same atomic mass
60. Match the items in column A with items in column B
Column - A Column - B
(i) Methane molecules (a) covalency
(ii) Sharing of electrons (b) tetrahedral molecules
(iii) H2O (c) pyramidal molecules
(iv) NH3 (d) polar molecule
61. Match the following
Column – A Column – B
(A) F (P) Least reactive in the group
(B) Cl (Q) Form inter halogen compounds
(C) Br (R) Most reactive in the group
(D) I (S) Highest electron affinity
62. Match the following
Column - A Column - B
(A) Compound (P) Starch in water
(B) Mixture (Q) Solid CO2
(C) Colloid (R) Glucose
(D) Dry ice (S) Sand in water
Comprehension
If a discharge is passed through hydrogen gas (H2) at low pressure, some hydrogen atoms are
formed, which emits light in the visible region. The light can be studied with a spectrometer and is
found to comprise a series of lines of different wavelengths. The lines become increasingly close
together as the wavelength decreases until the continuum is reached. Sommerfield explained the
splitting of lines by assuming that some of the orbits were elliptical, and that they processed in
space around the nucleus. For the orbit closest to the nucleus the principle quantum number n =
1, and this is a circular orbit. For the next orbit n = 2, both circular and elliptical orbits are
possible. To define an elliptical orbit a second quantum number k is required. The shape of
ellipse is defined by the ratio of the major and minor axis. Thus,
major axis n
minor axis k

where, k is called azimuthal quantum number and may have values from 1, 2,…n. Thus for n = 2,
n/k may have values 2/2 (circular) and 2/1 (elliptical orbit). The presence of these extra orbits
which have slightly different energies from each other accounts for the extra lines in the spectrum
revealed under high resolution. The original quantum number k now has been replaced by a new
quantum number , where = k – 1.
Read the above passage carefully and answer the questions given below it.
63. When the principle quantum number n = 3, how many orbitals are possible in the valence
shell of the atom?
(A) 8 (B) 9
(C) 3 (D) 4
64. Who introduced the concept of elliptical orbits?

10. (A) Bohr (B) Sommerfield
(C) de Broglie (D) Rutherford
65. For which of the following shells splitting of spectral lines does not occur?
(A) K (B) L
(C) M (D) All of these
66. The splitting of spectral lines in the presence of magnetic field is called
(A) Stark effect (B) Zeemann effect
(C) Thomson’s effect (D) None of these
A covalent bond, in which electrons are shared unequally and the bonded atoms acquire a partial
positive and negative charge, is called a polar covalent bond. Bond polarity is described in terms
of ionic character which usually increases with increasing difference in the electronegativity
between bonded atoms. The polarity of a molecule is indicated in terms of dipole moment ().
Similarly in ionic bond, some covalent character is introduced because of the tendency of the
cation to polarise the anion. The magnitude of covalent character in the ionic bond depends upon
the extent of polarization caused by cations.
In general:
It’s a vector quantity and is defined as the product of distance between two heteronuclei and
partial charge, developed on any of the two heteronuclei atoms. For example,
 
 
H Cl
 
Dipole moment  = x e
(i) Smaller the size of cation, larger is its polarizing power.
(ii) Larger the anion, more will be its polarisabilty.
(iii) Among two cations of similar size, the polarizing power of cations with pseudo-noble gas
configuration (ns2np6nd10) is larger than cation with noble gas configuration (ns2np6) e.g.
polarizing power of Ag+ is more than K+.
Read the above passage carefully and answer the questions given below it.
67. The decreasing order of polarity of the bond in NH3, PH3, AsH3 and SbH3 is in the order
(A) NH3 > PH3 > AsH3 > SbH3 (B) SbH3 > AsH3 > PH3 > NH3
(C) NH3 > AsH3 > PH3 > SbH3 (D) NH3 > SbH3 > AsH3 > PH3
68. Which has maximum covalent character?
(A) LiF (B) LiCl
(C) LiBr (D) LiI
69. Which is highest melting point halide?
(A) NaCl (B) NaBr
(C) NaF (D) NaI
70. The correct order of decreasing polarity is:
(A) HF > SO2 > H2O > NH3 (B) HF > H2O > SO2 > NH3
(C) HF > NH3 > SO2 > H2O (D) H2O > NH3 > SO2 > HF
The successive energies required to create more highly charged ions, M2+, M3+ … which are the
second, third… ionisation energies. The value of energies always increase with the degree of
ionization. When electrons are removed from the same shell, then one less electron left to repel
the others. The magnitude of the charge depends on the size of the orbital of electron. Electrons
in smaller orbitals are on average close with each-other and have more repulsion. Thus with
Be(2s2) the first two ionisation energies are 9.3 and 18.2 eV, whereas with Ca(4s2) the values are
6.1 and 11.9 eV.

11. 71. Four elements have the following first ionization energies in kJmol1
: 762, 709, 59 and
558. The elements are Ga, Ge, In and Sn (not in order). Which of these elements has the
ionization energy of 762 kJmol1
?
(A) In (B) Ga
(C) Sn (D) Ge
72. The correct order of arrangement of the first ionization energies of C, N, O and F
(in decreasing values) is
(A) C > N > O > F (B) O > N > F > C
(C) O > F > N > C (D) F > N > O > C
73. Consider the first ionization energies of the elements whose electronic configurations
corresponds to the following.
(i) [He]2s22p3 (ii) [He]2s22p4
(iii) [Ne]3s23p1 (iv) [Ar]3d104s1
Which of the above have highest ionization energies?
(A) (i) (B) (ii)
(C) (iii) (D) (iv)
74. Which of the following are isoelectronic species?
3 2 4 3
I CH , II NH , III NH , IV NH
  
   
(A) I, II and III (B) II, III and IV
(C) I, II and IV (D) II and I
75. Among the following ionization reactions, which one will have the maximum value of
ionization energy?
(A) Be Be
 (B) 2
Be Be
 

(C) Sr Sr
 (D) 2
Sr Sr
 

Mole is a unit to express the quantity of a substance. The quantity may be in terms of collection of
particles or mass of a substance or volume of a gas. A collection of 6.023 x 1023 particles
represents one mole quantity. 1 mole of a substance also means its gram atomic mass or gram
molecular mass. In case of gases, one mole of it occupies a definite volume under the given
conditions of pressure and temperature. If temperature is 273 K and pressure is one atm., volume
occupied by one mole of a gas is 22.4 litre.
Read the passage carefully and answer the questions given below it.
76. ‘Mole’ represents
(A) a definite quantity of a substance (B) a chemical unit
(C) volume of a gas (D) mass of substance
77. The number of electrons present in 4.2 g of azide ions, is: (where NA is Avogadro’s
number)
(A) 2.1 NA (B) 2.2 NA
(C) 2.4 NA (D) 3.4 NA
78. Total number of neutrons present in 18 ml of water at 4oC and 1 atm pressure is
(NA = Avogadro’s number)
(A) 10 NA (B) 8 NA
(C) 6 NA (D) 4 NA
79. A sample of CO2 occupies a volume of 224 ml at STP. Total number of O-atoms in the
sample is
(A) 1.2 x 1022 (B) 1.2 x 1021
(C) 6.02 x 1021 (D) 6.02 x 1024
80. A sample of pyrolusite is found to contain 18 NA (where NA is Avogadro’s number)
oxygen atoms. The weight of pyrolusite sample is
(A) 0.483 kg (B) 0.583 kg
(C) 0.683 kg (D) 0.783 kg

12. ANSWERS TO WORK BOOK
Subjective:
Board Type Questions
1. In a f subshell, 14 electrons can be accommodated, out of which 7 will have clockwise
spin. This is because an orbital can accommodate two electrons with opposite spin.
2. Bohr’s atomic model imposed the following restriction on the Rutherford model of atom.
Not all orbtits are allowed, only those are allowed in which the energy of the electrons in
quantized and angular momentum of electrons is an integral multiple of h/2.
3. Atomic number of oxygen = 8
 no. of protons = 8
Charge on a proton = 1.602  1019
coulombs
 Charge carried by oxygen nucleus
= 8  1.602  1019
= 1.2816  1018
coulombs
4. An atom may lose or gain electrons, but the number of protons remains constant till be
same atom exists.
5. The difference of energy is maximum between the first and the second orbit. As the value
of the principle quantum number increases, the difference between two successive orbits
decreases, after a certain value, the energy levels are so closely spaced that they seem
to all continuous.
6. The electric bulb emits light discontinuously but it appears to us to be continuously
coming. This is because the rate of emission of photons of light is very high of the order
of millions of photons per second (but the human eye can record discontinuity in events
occurring only upto 16 times per second). This discontinuity in the case of the radiations
of light coming from the electric bulb is too small to be recorded by human eye.
Consequently light appears as if is being continuously emitted.
7. H3O+ has pyramidal shape because O is surrounded by 3 bond pairs and 1 lone pair.
8. CaF2 is neither linear nor bent because it is an ionic compound and ionic bond is non
directional.
9. MgO has a higher lattice energy because each ion carries two unit charges whereas in
NaCl, each ion carries one unit charge.
10. NaCl is an ionic compound an hence gives Cl
ions in the solution which combines with
Ag+ ions given by AgNO3 to form a white precipitate of AgCl but CCl4 is a covalent
compound and does not give Cl
ions.
11. 2 2 3 4 3 2
C H BF CH NH H O
   
12. In NF3, N has the hybridization sp3 with one position occupied by lone pair of electrons
but in BF3, B has the hybridization sp2.

13. 13. The jump in IE are notices when the successive removal of electron occurs from different
shells. In alkali metals (ns1) removal of I and II electrons occurs from n, (n – 1) shells
respectively and thus shows a jump in IE2 values. This condition occurs during the
removal of II and III electrons from alkaline earth metals (ns2).
14. Since nitrogen atom has half filled p-orbitals hence it gets extra stability and has little
tendency to accept the electron. Therefore the electron affinity of nitrogen is lower than
that of carbon.
15. The noble gases group 0 or 18, have valence 8 electrons.
16. The electron affinity of a positive ion is merely the addition of an electron to that of ion,
therefore it is opposite of the ionization potential of the species with one lower positive
charge.
17. No element has a negative ionization potential that is all elements require energy to
remove an electron from a gaseous atom to form a gaseous ion.
18. Since loss of electron is oxidation and gain of electrons is reduction, the species which
lose electrons easily are good reducing agents. The electropositive elements have
greater tendency to lose electrons, therefore they are good reducing agents.
19. 4  102
mol
20. 55.9
21. 10 g O2 = 3.76  1023 atoms
10 g O3 = 3.76  1023 atoms
Both the bulbs contain same numbers of atoms but bulbs B1 contains more number of
molecules.
22. Because atomic masses are the average of different isotopes of that element.
23. 1 g atom of iron means atomic mass of iron expressed in gram i.e. 56 g.
24. (a) 1.235  107 (b) 2.355
(c) 4.565  105 (d) 3.218  103
True/False
25. False 26. True
27. False 28. False
29. False 30. True
31. False 32. True
Fill in the Blanks
33. Approximately equal 34. Zero
35. Two 36. 0.5
37. Greater nuclear charge 38. Greater
39. 4.14 g 40. Element

14. IIT Level Questions
41. 1.25  1013
42. v = v
i.e., velocity is completely uncertain.
43. The electron jumps to 3rd energy level.
46. Mg+ 68.35%; Mg2+ 31.65%
47. Paramagnetic species: Cr3+, Co3+
Diamagnetic species: Na+, Zn2+, Cl
, Cd2+, Sn2+
48. 8.6 g CO2 released Volume at NTP =
22.4
8.6 4.378
44
 
49. 0.477 g
50. MO2 and M2O3

15. Objective:
Single Correct Questions
1. D 2. C 3. C 4. B
5. C 6. D 7. A 8. B
9. C 10. A 11. A 12. A
13. B 14. B 15. D 16. B
17. A 18. B 19. C 20. D
21. C 22. C 23. B 24. C
25. A 26. C 27. A 28. A
29. D 30. D 31. B 32. D
33. C 34. A 35. D 36. B
37. C 38. A 39. A 40. D
Multiple Correct Questions
41. A & C 42. B & C 43. C & D 44. C & D
45. A, B & D 46. A,B,C 47. A,B,C 48. B,C,D
49. A,C 50. A,B,C 51. A,C,D
52. A,B,C,D 53. C,D 54. A,C,D
55. A,B,C,D 56. A,C 57. B,C 58. A,B
Match the Following
59. (i)(d), (ii)(c), (iii)(b), (iv)(a)
60. (i)-(b); (ii)–(a); (iii)-(d); (iv)-(c)
61. (A)–Q & R, (B)–Q & S, (C)–Q, (D)–P & Q
62. (A) – Q & R, (B) – P & S, (C) – P, (D) – Q
Comprehension
63. B 64. B 65. A 66. B
67. A 68. D 69. C 70. B
71. D 72. D 73. A 74. B
75. B 76. B 77. B 78. B
79. A 80. D