Among the following, the species having square planar geometry for central atom are
(i) XeF4, (ii) SF4, (iii) [NiCl4]2- ,(iv) [PdCl4 ]2-
(i) and (iv)
(i) and (ii)
(ii) and (iii)
(iii) and (iv).
A.
(i) and (iv)
XeF4 : sp3 d2 hybridisation, shape is square planar instead of octahedral due to presence of two lone pair of electrons on Xe atom. SF4: SF4 molecule shows sp3d hybridisation but its expected trigonal bipyramidal geometry gets distorted due to presence of a lone pair of electrons and it becomes distorted tetrahedral or see-saw with the bond angles equal to 89° and 177° instead of the expected angles of 90° and 180° respectively.
Experiments have, however, shown that 4-coordinated complexes of Pd(II) are diamagnetic (n = 0). Thus it is dsp2 hybridisation which is involved in the formation of (PdCl4]2- ion i.e. 4-coordinated complexes of Pd(II) have square planar geometry with n = 0 (diamagnetic).
The de Broglie wavelength associated with a ball of mass 1kg having kinetic energy 0.5 J is
6.626 10-34 m.
13.20 10-34 m.
10.38 10-21m.
6.626 10-34.
Dominance of strong repulsive forces among the molecules of the gas (Z = compressibility factor)
depends on Z and indicated by Z = 1
depends on Z and indicated by Z > 1
depends on Z and indicated by Z < 1
is independent of Z.
40 mL of 0.1 M ammonia solution is mixed with 20 mL. of 0.1 M HCl. What is the pH of the mixture? (pKb, of ammonia solution is 4.74)
4.74
2.26
9.26
5.00
For a spontaneous process the correct statement is
entropy of the system always increases.
free energy of the system always increases.
total entropy change is always negative.
total entropy change is always positive.
The enthaply change () for the reaction
is -92.38 kJ at 298K . The internal energy change at 298K is
-92.38 kJ
-87.42 kJ
-97.34 kJ
-89.9 kJ
Assertion : Molecular nitrogen is less reactive than molecular oxygen.
Reason : The bond length of N2 is shorter than that of oxygen.
If both assertion and reason are true and reason is the correct explanation of the assertion.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
If assertion is true, but reason is false.
Both assertion and reason are false statements.
Assertion : Water in liquid state is more stable than ice at room temperature.
Reason : Water in liquid form has higher entropy than ice.
If both assertion and reason are true and reason is the correct explanation of the assertion.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
If assertion is true, but reason is false.
Both assertion and reason are false statements.
Borax is used as a cleansing agent because on dissolving in water it gives
alkaline solution
acidic solution
bleaching solution
basic solution.