Which ofthe following complexes exists as pair of enantiomers ?
trans-[Co(en)2Cl2]+
[Co(NH3)2Cl2]+
[Co{P(C2H5)3}2ClBr]
[Cr(en)3]3+
Which of the following compounds is aromatic in nature?
A.
Among all the given options, option a is correct.
It is due to the presence of (4n + 2) e- it follows Huckel's rule and therefore, it is aromatic.
In option b, due to te presence of extra lone pair of electrons, total e- comes out to be 4e-. Thus, it is anti-aromatic.
In option c, although it is cyclic and has conjugated 8e- but Huckel's (4n + 2) rule is not followed and also ring is not planar. Hence, it is non- aromatic.
In option d, it has 6e- in conjugation but not in the ring, hence it is non - aromatic.
What is the correct order of basicity among the following compounds ?
II > I > III > IV
I > II > III > IV
III > I > II > IV
I > III > II > IV
Arrange the following nucleophiles in the decreasing order of nucleophilicity :
(A) CH3COO-
(B) CH3O-
(C) CN-
(D)
C, B, A, D
A, B, C, D
C, C, B, A
B, C, A, D
Assertion : Thiophene present in commercial benzene as an impurity can be removed by shaking the mixture with cold concentrated H2SO4.
Reason : Thiophene is a heterocyclic aromatic compound.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
Ease of nucleophilic addition in the given compounds is
I > III > II
II > III > I
II > I > III
III > I > II
Which of the following species is not aromatic?
Benzene
Cyclooctatetraenyl dianion
Tropylium ion
Cyclopentadienyl cation
Select the correct statement.
Geometrical isomer may differ in dipole moment and visible/UV spectra.
Complexes of the type [Ma3b3] can also have facial (fac) and meridional (mer) isomer.
No optical isomer exists for the complex trans- [Co(en)2Cl2]+.
All of these.