Solid A is very hard electrical insulator in solid as well as in molten state and melts at an extremely high temperature. What type of solid is it?
(A) Ionic solid
(B) Molecular solid
(C) Covalent solid
(D) Metallic solid
(A) Ionic solid
(B) Molecular solid
(C) Covalent solid
(D) Metallic solid
(C) Covalent solid
Graphite cannot be classified as __________.
(A) Conducting solid
(B) Network solid
(C) Covalent solid
(D) Ionic solid
The lattice site in a pure crystal cannot be occupied by __________.
(A) Molecule
(B) Ion
(C) Electron
(D) Atom
What is the coordination number in a square close packed structure in two dimensions?
(A) 2
(B) 3
(C) 4
(D) 6
Which of the following conditions favours the existence of a substance in the solid state?
(A) High temperature
(B) Low temperature
(C) High thermal energy
(D) Weak cohesive forces
Which of the following Defects is also known as dislocation defect?
(A) Frenkel defect
(B) Schottky defect
(C) Non-stoichiometric defect
(D) Simple interstitial defect
Which stoichiometric defect does not change the density of the crystal?
(A) Frenkel defect
(B) Schottky defect
(C) Interstitial defect
(D) F-centres
The total number of tetrahedral voids in the face centred unit cell is _____.
(A) 6
(B) 8
(C) 10
(D) 12
On a large-scale nitric acid is prepared mainly by
a) Haber's process
b) Ostwald’s process
c) Contact Process
d) Deacon's process
There is a considerable increase in covalent radius from N to P. However, from As to Bi only a small increase in covalent radius is observed. This is due to
a) Increase in number of shells
b) increase in valence electrons
c) increase in ionisation enthalpy
d) the presence of completely filled d and/or f orbitals
Hypochlorous acid and perchloric acid are, respectively:
a) HOCl and \(HClO_4\).
b) HOCl and \(HClO_3\).
c) \(HClO_2\) and \(HClO_3\).
d) \(HClO_2\) and \(HClO_4\).
The sharp melting point of crystalline solids is due to ___________.
(A) a regular arrangement of constituent particles observed over a short distance in the crystal lattice.
(B) a regular arrangement of constituent particles observed over a long distance in the crystal lattice.
(C) same arrangement of constituent particles in different directions.
(D) different arrangements of constituent particles in different directions.
The decreasing order of boiling point of the following alcohols is
(a) 3-methylbuan-2-ol > 2-methylbutan-2-ol > pentan-1-ol.
(b) Pentan-1-ol > 3-methylbutan-2-ol > 2-methylbutan-2-ol.
(c) 2-methylbutan-2-ol > 3-methylbutan-2-ol > pentan-1-ol.
(d) 2-methylbutan-2-ol > pental-1-ol > 3-methylbutan-2-ol.
In the periodic table of the elements, the phrase “middle row anomaly” refers to
a) Middle elements of periodic table are transition metals.
b) Middle element of each group is unstable.
c) the relative instability of bromine oxides compared to the other halogen oxides.
d) The higher oxides of halogens tend to be more stable than the lower ones.
Which of the following conditions favours the existence of a substance in the solid state?
(A) High temperature
(B) Low temperature
(C) High thermal energy
(D) Weak cohesive forces