Multiple Choice QuestionsThe correct order of decreasing dipole moment of (I) toluene, (II) m-dichlorobenzene (III) o-dichlorobenzene and (IV) p-dichlorobenzene is
IV < II < I < III
IV < I < II < III
I < IV < II < III
IV < I < III < II
B.
IV < I < II < III
Dipole moment of p-dichlorobenzene is zero, while that of o-dichlorobenzene is 2.54 D and for m-dichlorobenzene is 1.48 D. This shows that benzene ring is planar and in p-C6H4Cl2 two C-Cl bonds are directed in the plane of the ring, thus on adding, they becomes zero. In this, two C-Cl bonds contain an angle of 60° and in m- C6H4Cl2 the two C-Cl bonds contain an angle of 120° and their dipole moments on vector addition give a higher value of dipole moment.
Therefore, sequence of dipole moment is as follows:
p-dichlorobenzene < toulene < m-dichlorobenzene < o-dichlorobenzene
Which one of the following complexes is an outer orbital complex?
(Atomic number of Mn = 25; Fe = 26; Co = 27 and Ni = 28)
[Fe(CN)6]4-
[Mn(CN)6]4-
[Co(NH3)6]3+
[Ni(NH3)6]2+
For a gas in equilibrium with a liquid, the ratio of the concentration of the gas in the solution phase to that in the gaseous phase is constant at constant temperature, only if molecules undergo
ionisation
dissociation
isolation
reaction with solvent
IUPAC name of the compound is
2-methyl-6-ethyloct-1, 5-dienal
3-ethyl-7-methyloct-2, 6-dienal
7-methyl-3-ethyloct-2, 6-dienal
None of the above
Iron pipes, lying in acidic soil, are often attached to the blocks of magnesium for their protection from rusting, because magnesium
is lighter than iron
is readily converted into positive ion
forms a corrosion-resistant alloy with iron
prevents air from reaching the surface of iron
The number of sodium atoms in 2 moles of sodium ferrocyanide is
12 × 1023
26 × 1023
34 × 1023
48 × 1023
Match the Column I and Column II and choose the correct code given below.
| Column I | Column II |
| A. Peroxyacetyl nitrile | i. Waste incineration |
| B. Indigo | ii. Vat dye |
| C. IR active molecules | iii. Global warming |
| D. Dioxins | iv. Photchemical smog |
A - iv; B - ii; C - iii; D - i
A - i; B - ii; C - iv; D - iii
A - ii; B - i; C - iv; D - iii
A - iv; B - i; C - iii; D - ii
The densities of graphite and diamond at 298 K are 2.25 and 3.31 g cm-3 respectively. If the standard free energy difference is 1895 J mol-1, the pressure at which graphite will be transformed into diamond is
9.92 × 108 Pa
9.92 × 107 Pa
9.92 × 106 Pa
None of these
Switch
