21648.For the properties mentioned, the correct trend for the different species is in
strength as Lewis acid – BCl3 > AlCl3 > GaCl3
inert pair effect – Al > Ga > In
oxidising property – Al+3 > In+3 > Tl+3
first ionization enthalpy – B > Al > Tl
21649.What is the geometry of molecule of bromine penta fluoride ?
square planar
trigonal bipyramidal
square pyramidal
octahedral
21650.In Ramsay and Rayleigh’s isolation of noble gases from air, the nitrogen of the air is finally converted into
NO and NO2
NaNO2 only
NaNO2 and NaNO3
NaNO3 only
21652.Argon is used
To obtain low temperature
In high temperature welding
In radio therapy for treatment of cancer
In filling airships
21653.Molecules of a noble gas do not possess vibrational energy because a noble gas ______.
is chemically inert
is monoatomic
is diamagnetic
has completely filled shells
21654.Oxidation number of nitrogen in which among the oxides of nitrogen is the lowest?
Nitric oxide
Nitrous oxide
Nitrogen dioxide
Nitrogen trioxide
21655.Which one of the following is the correct statement?
Boric acid is a protonic acid
Beryllium exhibits coordination number of six
Chlorides of both beryllium and aluminium have bridgedchloride structures in solid phase
B2H6.2NH3 is known as ‘inorganic benzene’
21657.Atoms in a P4 molecule of white phosphorus are arranged regularly in the following way
at the corners of the cube
at the corners of the octahedron
at the corners of a tetrahedron
at the centre and corners of a tetrahedron