Some basic concepts
SI unit of Molar Mass is?
kg/mol
The nucleus atom consists of?
Protons and neutrons
Which of the following is a noble gas?
a) Fluorine
b) Neon
c) Lithium
d) Oxygen
b) Neon
Which of the following molecules has a linear shape?
a) H₂O
b) NH₃
c) BeCl₂
d) CH₄
c) BeCl₂
Who discovered the neutron?
a) J.J. Thomson
b) Rutherford
c) Chadwick
d) Goldstein
c) Chadwick
Which of the following is an intensive property?
Temperature
Principal, Azimuthal and magnetic quantum numbers are respectively related to:
(a) Size, shape and orientation
(b) Shape, size and orientation
(c) Size, orientation and shape
(d) None of the above
(a) Size, shape and orientation
The number of periods in the modern periodic table is:
a) 7
b) 8
c) 9
d) 18
a) 7
The geometry of SF₆ molecule is:
a) Tetrahedral
b) Octahedral
c) Trigonal bipyramidal
d) Square planar
b) Octahedral
Which of the following has the largest atomic radius?
a) Li
b) Na
c) K
d) Rb
b) Na
If 2.76 g of silver combines with 0.72 g of chlorine to form AgCl, the equivalent mass of silver is:
108
State True or False:
Isotopes have the same mass number but different atomic numbers
False: they have the same atomic number but different mass number
Elements of group 17 are called:
a) Noble gases
b) Halogens
c) Alkali metals
d) Alkaline earth metals
b) Halogens
State True or False:
Lone pairs of electrons cause more repulsion than bond pairs.
True
The bond angle in H₂O is less than that in NH₃ because:
a) Lone pair–lone pair repulsion is less than bond pair–bond pair repulsion
b) Lone pair–bond pair repulsion is greater than bond pair–bond pair repulsion
c) Electronegativity of O is less than that of N
d) Water has hydrogen bonding
b) Lone pair–bond pair repulsion is greater than bond pair–bond pair repulsion
The significant figures in 0.000051 are?
2
According to Bohr’s model, the angular momentum of an electron is quantized as:
a) nh/2π
b) nh
c) h/2πn
d) 2πn/h
a) nh/2π
The radius of atoms __________ across a period from left to right.
a) Increases
b) Decreases
c) Remains the same
d) First increases then decreases
b) Decreases
State True or False:
According to MOT, O2 is diamagnetic
False
The energy of an electron in the second Bohr orbit of hydrogen is:
a) –13.6 eV
b) –3.4 eV
c) –6.8 eV
d) –1.7 eV
b) –3.4 eV
A measured temperature on Fahrenheit scale is 200F. What will this reading be on the Celsius Scale?
93.3 degree Celsius
Which orbital has a spherical shape?
s orbital
Across a period, electronegativity.........
Increases
Which of the following has sp² hybridization?
a) CO₂
b) CH₄
c) BF₃
d) NH₃
c) BF₃
Which of the following is paramagnetic and has a bond order of 2.5?
a) O₂
b) O₂⁻
c) N₂
d) CO
b) O₂⁻