Which of the following statements is not true about amorphous solids?
(A) On heating they may become crystalline at certain temperature.
(B) They may become crystalline on keeping for long time.
(C) Amorphous solids can be moulded by heating.
(D) They are anisotropic in nature.
(A) On heating they may become crystalline at certain temperature.
(B) They may become crystalline on keeping for long time.
(C) Amorphous solids can be moulded by heating.
(D) They are anisotropic in nature.
(D) They are anisotropic in nature.
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 is true about the value of refractive index of quartz glass?
(A) Same in all directions
(B) Different in different directions
(C) Cannot be measured
(D) Always zero
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 of the following is an amorphous solid?
(A) Graphite (G)
(B) Quartz glass (SiO2)
(C) Chrome alum
(D) Silicon carbide (SiC)
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
Which stoichiometric defect does not change the density of the crystal?
(A) Frenkel defect
(B) Schottky defect
(C) Interstitial defect
(D) F-centres
Which of the following statement is false?
a) Radon is obtained from the decay of radium
b) Helium is an inert gas
c) Xenon is the most reactive among the rare gases
d) The most abundant rare gas found in the atmosphere is helium
An antifreeze solution is prepared from 222.6 g of ethylene glycol \(C_2\)\(H_4\)\((OH)_2\) and 200 g of water. Calculate the molality of the solution. If the density of this solution be 1.072 \(gmL^{-1}\), what will be the molarity of the solution?
(a) 7.20 M
(b) 12.03 M
(c) 9.11 M
(d) 6 M
The molal elevation constant depends upon
(a) nature of solute.
(b) nature of the solvent.
(c) vapour pressure of the solution.
(d) enthalpy change.
Which of the following factors is not responsible for the denaturation of proteins?
(a) Heat
(b) Charge
(c) pH change
(d) Organic solvents
Which cell will measure standard electrode potential of copper electrode?
a. Pt (s) | H₂ (g, 0.1 bar) | H⁺ (aq., 1 M)
When KMnO₄ solution is added to oxalic acid solution, the decolourisation is slow in the beginning but becomes instantaneous after some time because
(a) CO₂ is formed as the product.
(b) The reaction is exothermic.
(c) MnO₄⁻ catalyses the reaction.
(d) Mn²⁺ acts as an auto-catalyst.
Which of the following alcohols gives 2-butenc on dehydration by conc.\(H_2\)\(SO_4\)?
(a) 2-methyl propene-2-ol.
(b) 2-methyl 1 -propanol.
(c) Butane-2-ol.
(d) Butane 1-ol.