Transcript Q: 1. The lowest first ionisation energy would be associated with which of the following structures? a] 1s2 2s2 2p6 3s1 b] 1s2 2s2

Q: 1. The lowest first ionisation energy would be
associated with which of the following
structures?
a] 1s2 2s2 2p6 3s1
b] 1s2 2s2 2p5
c] 1s2 2s2 2p6
d] 1s2 2s2 2p6 3s2 3p2
Ans : a] 1s22s2 2p6 3s1
Q: 2. Which of the following combinations
contains only isoelectronic species?
-
a] N3-, O2-, Cl
2-,
b] F , Ar, S Cl
c] P3-,S2-, Cld] N3-, F , O2-, Ar
Ans: c]
P3-,S2-
,Cl
Q: 3. Fluorine has unexpectedly lower electronic
affinity than that of chlorine due to.
a]
b]
c]
d]
Ans: b]
Big size of fluorine, which results in
increase in the electron-electron
repulsion 2P subshell
Small size of fluorine, which results in
increase in the electron-electron
repulsion 2p-subshell.
Decrease in electron-electron repulsion
No electron-electron repulsion in 2psubshell
Small size of fluorine, which results in
increase in the electron-electron
repulsion 2p-subshell
Q: 4. The most electronegative element in the
periodic table is.
a] Nitrogen
b] Oxygen
c] Chlorine
d] Fluorine
Ans: d] Fluorine
Q: 5. Which one of the following has the smallest
radius?
a] Cl
b] S2c] K+
d] Ca2+
Ans: d] Ca2+
Q: 6. Atomic size increase as we move down a
group because.
a] effective nuclear charge increases
b] Atomic mass increases.
c] Additive elements are accommodated in new
electron level.
d] Atomic number increases.
Ans: c]
Additive elements are accommodated in
new electron level.
Q: 7. Electrons which are characterised by the
outer shell configuration ns1 to ns2 np6 are
collectively called.
a) transition elements.
b) representative element .
c) lanthanides.
d) inner transition elements
Ans:
b) representative element .
Q:8. Atomic numbers of V,Cr, Mn and Fe are
23,24,25and 26 respectively, which one of
these may have the highest second
ionisation potential
a) Mn
b) Fe
c) v
d) Cr
Ans:-
d) Cr
E.c- of Cr – 3d5 ,4s1, as 3d- orbital is
exactly half filled, removal of election is
difficult.
Q: 9. Diagonal relationship is shown by
a) all elements with their diagonally opposite
elements.
b) all elements of 3rd and 4th periods
c) some elements of 2nd and 3rd periods.
d) elements of d-block.
Ans: c) some elements of 2nd and 3rd periods.
Q :10. Lithium is not stored in kerosene. It is
kept wrapped in paraffin wax because
a) it reacts with kerosene .
b) Lithium floats over kerosene as its
density is low
c) Lithium is a soft metal.
d) Lithium sinks in kerosene
Ans : b) Lithium floats over kerosene as its
density is low .
Q : 11. compounds of group 2 elements are less
soluble in water than the corresponding
alkali metal salts due to
a) their high ionisation energy
b) their high lattice energy
c) less basic character
d) low electronegativity values.
Ans : b) their high lattice energy
Q :12. The Density of “Ca” is less than that of “Mg”
because
a) Nuclear charge of “Ca” is more than “Mg”
b) Size of “Ca” is less than “Mg”
c) Vacant 3d orbital of “Ca”
d) completely filled 3d orbital’s .
Ans: c) Vacant 3d orbital of “Ca”
leads to the much increasing atomic
volume hence density decreases
Q :13. Oxide of an element whose electronic
configuration is 1s22s22p63s1 is
a) Basic
b) Acidic
c) neutral
d) Amphoteric
Ans: a) Basic
Q : 14. carbon -60, contains
a) 12 five membered and 20- six membered
rings
b) 12 five membered and 20- five membered
rings
c) Same no of five and six membered rings
d) No five and six membered rings
Ans: a) 12 five membered and 20- six memberd
rings
Q :15. A radio station broadcasts on a frequency of
1368 KHz, what is the wavelength of
electromagnetic radiation emitted by
transmitter
a) 219300m
b) 219.3m
c) 2.1933m
d) 0.2193m
Ans:
b) 219.3m
C = 3 x 108 m/s λ = ?
=
=
3 x 108
1368 x 103
= 219.3 m
Q :16.
Energy of a wave of wavelength
400A0 is
a) 495 x 10-19J
b) 4.95 x 10-18J
c) 4.95 x 10-19J
d) 495 x 10-18J
Ans: c)
4.95 x 10-19J
λ = 400 A0 = 400 x 10-10 m
E=h
=h
= 6.6 x 10-34 x 3 x 108
400 x 10-10
E = 4.95 x 10-19J
Q : 17. What will be de- Broglie wave length of an
electron moving with a velocity of
1.2 x10-5m/s
a) 6.068 x 10-9m
b) 3.133 x 10-37 m
c) 6.626 x 10-9 m
d) 6.018 x 10-7 m
Ans:
A) 6.068 x 10-9 m
λ = h/mc
h = 6.62 x 10-34 js
m = 9.1 x 10-31 Kg
c = 1.2 x 105 m/s
λ=
Q:18 . The Quantum numbers for the last electron
of an element are given below
n = 2, l = 0, m = 0, s = + 1/2 , The atom is
a) Lithium
b) Beryllium
c) Hydrogen
d) Boron
Ans: a) Lithium
Q:19. Which of the following set of Quantum
numbers is not possible
a)
b)
c)
d)
n
3
3
3
3
l
2
2
2
2
Ans: a) n=3 l=2 m=-1 s=0
m
-1
-1
1
1
s
0
+½
+½
-½
Q:20. Total number of neutrons in dipositive zinc ion
with mass 70 is
a) 34
b) 40
c) 36
d) 38
Ans b) 40
A = 70,
z = 30
n = A-z
= 40
Q:21. Orbital angular momentum of an electron in
2s orbital is
A] + ½ h/2π
B] h/2π
C] √2 h/2π
D] Zero
Ans: d] Zero
Orbital angular momentum = l h/2π
For ‘S’ orbital l=0
0 x h/2π = 0
Q: 22. What is the wave number of radiation emitted
when an electron jumps fro n =3 to n= 1 in a
hydrogen atom (R=107/m)
a) 1.11 x 108/m
c) 8.9 x 106/m
Ans: c) 8.9 x 106/m
b) 8.9 x 108/m
d) 8.9 x 107/m
Q : 23.
The ion that is isoelectronic with CO is
a)
b)
c)
d) CN
Ans :
-
CN
No of electrons in co = 6+8 = 14
In CN
6+7+1 = 14
Q: 24. It is impossible to measure simultaneously
the position and momentum of a small particle
with absolute accuracy, This is stated by
a) Hund
b) pauli
c) Heisenberg
d) Bohr
Ans :
c) Heisenberg
Q : 25. 4s orbital gets filled before 3d because
a) 4s has more energy than 3d
b) 4s has same energy energy as that 3d
c) ( n + 1 ) Value for 4s is more than 3d
d) ( n + 1 ) Value for 4s is less than 3d
Ans:
d) ( n + 1 ) Value for 4s is less than 3d