According to Molecular Orbital Theory, which of the following statement is incorrect?
1. C2 has no unpaired electrons.
2. In C2 molecule, both the bonds π are bonds.
3. C2 is paramagnetic but C22-is diamagnetic.
4. In C22- ion, there is one σ and two π bonds.
Match the ionization processes listed in column I with the changes observed as listed in column II. For this use the codes given below:
Column I | Column II | ||
(a) | N2→N+2 | (p) | Bond order increases and magnetic property is changed. |
(b) | O+2→O2+2 | (q) | Bond order decreases and magnetic property is not changed. |
(c) | B2→B+2 | (r) | Bond order increases and magnetic property is not changed. |
(d) | NO−→NO | (s) | Bond order decreases and magnetic property is changed. |
Note: Here change in magnetic property refers to the change from diamagnetic to paramagnetic
or paramagnetic to diamagnetic.
a | b | c | d | |
1. | s | q | p | r |
2. | s | p | q | r |
3. | r | q | s | p |
4. | p | s | q | r |
A diatomic molecule has a dipole moment of 1.2 D. If its bond length is equal to 10 -10 m , then the fraction of an electronic charge on each atom will be:
1. 42%
2. 52%
3. 37%
4. 25%
Arrange the following molecules from most to least polar.
CH4 CF2Cl2 CF2H2 CCl4 CCl2H2
I II III IV V
(1) III>V>II > IV=I
(2) II>IV>III>IV>I
(3) III>II>V>IV>I
(4) V>III>II>IV=I
Which of the following statements is/are correct?
1. | (CH3)3COH is less acidic than (CH3)3SiOH |
2. | CO, its analogue Si is not stable. | Like
3. | C−O bond length is longer than expected while C−Cl bond length is shorter. | In phosgene,
4. | All of the above. |
The increasing order of the strength of hydrogen bond in the following mentioned linkages
is
(i) O — H — S (ii) O — H — O (iii) F – H – F (iv) F – H – O
(1) (i) < (ii) < (iv) < (iii)
(2) (ii) < (i) < (iv) < (iii)
(3) (i) < (ii) < (iii) < (iv)
(4) (ii) < (i) < (iii) < (iv)
The boiling point of CCl4 is higher than that of CHCl3 because :
(1) The dipole moment of CCl4 is greater than that of CHCl3
(2) CCl4 forms hydrogen bonds.
(3) CCl4 has higher molecular mass than that of CHCl3
(4) CCl4 is more ionic than CHCl3
Assertion : Compounds of Hg2+ ions having an ionic radius of 116 pm are move covalent in character
than those of Ca2+ ions with almost identical size (114 pm) and the same charge.
Reason : For two ions of the same size and charge, one with an (n-1)d10ns0. electronic configuration
will be more polarizing than a cation with an (n-1)s2 (n-1)p6ns0, electronic configuration.
Assertion : In tetrahedral hybridisation i.e., in sp3 hybridisation all p-orbitals are involved and no
p-orbital is left for coming with π-bonds.
Reason : Central atom can not form double bonds in the molecules or species having sp3hybridisation.
Assertion : F bond angle P = bond angle Q but not precisely 90°.
Reason : The molecule is slight bent T-shaped and there is repulsion between lone pairs of electrons.