Which of the following factors is of no significance for roasting sulphide ores to the oxides and not subjecting the sulphide ores to carbon reduction directly?
is more volatile than
Metal sulphides are thermodynamically more stable than
is thermodynamically more stable than
Metal sulphides are less stable than the corresponding oxides
The organic chloro compound, which shows complete stereochemical inversion during a reaction, is
Bakelite is obtained from phenol by reaction with
In context with the industrial preparation of hydrogen from water gas , which of the following is the correct statement?
is oxidised to with steam in the presence of a catalyst followed by absorption of in alkali
and are fractionally separated using differences in their densities
is removed by absorption in aqueous solution
is removed through occlusion with Pd
Identify the wrong statement in the following.
Acid rain is mostly because of oxides of nitrogen and sulphur
Chlorofluorocarbons are responsible for ozone layer depletion
Greenhouse effect is responsible for global warming
Ozone layer does not permit infrared radiation from the sun to reach the earth
Which one of the following is the correct statement?
is known as ‘inorganic benzene’
Boric acid is a protonic acid.
Beryllium exhibits coordination number of six
Chlorides of both beryllium and aluminium have bridged chloride structures in solid phase
Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids, the main reason being
More reactive nature of the actinoids than the lanthanoids
orbitals more diffused than the orbitals
Lesser energy difference between and than between and orbitals
More energy difference between and than between and orbitals
The potential for the cell
Amount of oxalic acid present in a solution can be determined by its titration with solution in the presence of . The titration gives unsatisfactory result when carried out in the presence of , because
oxidises oxalic acid to carbon dioxide and water
gets oxidised by oxalic acid to chlorine
Furnishes ions in addition to those from oxalic acid
reduces permanganate to
The value of is
For a reaction rate of disappearance of is related to the rate of appearance of by the expression
Oxidising power of chlorine in aqueous solution can be determined by the parameters indicated below:
The energy involved in the conversion of (using data , = 240 kJ mol-1 , = = -349 kJ mol-1, = -381 kJ mol-1) will be
+120 kJ mol-1
+152 kJ mol-1
-610 kJ mol-1
-850 kJ mol-1
Standard entropy of are 60, 40 and 50 J K-1 mol-1, respectively. For the reaction,
to be at equilibrium, the temperature will be
Let . Then which one of the following is true?
An experiment is performed to find the refractive index of glass using a travelling microscope. In this experiment distances are measured by
a screw gauge provided on the microscope
a vernier scale provided on the microscope
a standard laboratory scale
a meter scale provided on the microscope.
Two full turns of the circular scale of a screw gauge cover a distance of 1 mm on its main scale. The total number of divisions on the circular scale is 50. Further, it is found that the screw gauge has a zero error of – 0.03 mm. While measuring the diameter of a thin wire, a student notes the main scale reading of 3 mm and the number of circular scale divisions in line with the main scale as 35. The diameter of the wire is
A horizontal overhead powerline is at a height of 4 m from the ground and carries a current of 100 A from east to west. The magnetic field directly below it on the ground is
Relative permittivity and permeability of a material are , respectively. Which of the following values of these quantities are allowed for a diamagnetic mateiral?
A parallel plate capacitor with air between the plates has a capacitance of 9pF. The separation between its plates is d . The space between the plates is now filled with two dielectrics. One of the dielectrics has dielectric constan k1 = 3 and thickness d/3 while the other one has dielectric constant k2 = 6 and thickness 2d/3 Capacitance of the capacitor is now
As we learnt in
Parallel Plate Capacitor -
Area - A seperation between two plates.
If K filled between the plates -
(as they are in series)