The structure of diborane (B2H6) contains:

1. four 2C-2e- bonds and four 3C-2e- bonds
2. two 2C-2e- bonds and two 3C-3e- bonds
3. two 2C-2e- bonds and four 3C-2e- bonds
4. four 2C-2e- bonds and two 3C-2e- bonds

Subtopic:  Compounds of Boron- Preparations, Properties & Uses |
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Level 2: 60%+
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Aluminium chloride exists as dinner, Al2Cl6 in the solid state as well as in the solution of non-polar solvents such as benzene. When dissolved in acidified aqueous solution, it gives:

1. \(\mathrm{Al}^{3+}+3 \mathrm{Cl}^{-}\)

2. \(\left[\mathrm{Al}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}+3 \mathrm{Cl}^{-} \)

3. \(\left[\mathrm{Al}(\mathrm{OH})_{6}\right]^{3-}+3 \mathrm{HCl}\)

4. \(\mathrm{Al}_{2} \mathrm{O}_{3}+6 \mathrm{HCl}\)

Subtopic:  Boron Family- Preparations, Properties & Uses |
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Level 2: 60%+
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In the structure of silicon dioxide:

1. There are double bonds between silicon and oxygen atoms.
2. Silicon atom is bonded to two oxygen atoms.
3. Each silicon atom is surrounded by two oxygen atoms and each oxygen atom is bonded to two silicon atoms.
4. Each silicon atom is surrounded by four oxygen atoms and each oxygen atom is bonded to two silicon atoms.

Subtopic:  Properties of Structure of SiO2 & Other Compounds |
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Graphite is a soft solid lubricant extremely difficult to melt. The reason for this anomalous behavior is that graphite : 

1. is a non-crystalline substance. 
2. is an allotropic form of diamond. 
3. has molecules of variable molecular masses like polymers. 
4. has carbon atoms arranged in large plates of rings of strongly bound carbon atoms with weak interplate bonds. 

Subtopic:   Structure & Properties of Allotropes of C |
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Level 1: 80%+
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The bond dissociation energy of B – F in BF3 is 646 kJ mol–1 , whereas that of C – F in CF4 is 515 kJ mol–1. The correct reason for the higher B-F bond dissociation energy as compared to that of C-F is :

1. Smaller size of B-atom as compared to that of C-atom

2. Stronger σ bond between B and F in BF3 as compared to that between C and F in CF4

3. Significant pπ − pπ interaction between B and F in BF3 whereas there is no possibility of such interaction between C and F in CF4

4. Lower degree of pπ − pπ interaction between B and F in BF3 than that between C and F in CF4

Subtopic:  Anomalous Behaviour of B & C |
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Level 3: 35%-60%
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In view of the signs of rG° for the following reactions:

PbO2+Pb2PbO,ΔrG<0SnO2+Sn2SnO,ΔrG>0

The oxidation states more characteristic for lead and tin are respectively:

1. For lead +2, for tin +2

2. For lead +4, for tin +4

3. For lead +2, for tin +4

4. For lead +4, for tin +2 

Subtopic:  Properties of Glass, Pb & Sn compounds |
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Level 1: 80%+
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Which one of the following boron anions cannot be formed?

1. BF63−

2. BH4

3. B(OH)4

4. BO33-

Subtopic:  Boron Family- Preparations, Properties & Uses |
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Which among the following halides is inert towards hydrolysis?

1. BF3

2. SiCl4

3. PCl5

4. SF6

Subtopic:  Boron Family- Preparations, Properties & Uses |
Level 4: Below 35%
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The correct statement about B2H6 is:

1. The terminal B–H bonds have less p-character when compared to bridging bonds.
2. The two B–H–B bonds are not of the same length.
3. All B–H–B angles are 120°.
4. Its fragment, BH3, behaves as a Lewis base.
Subtopic:  Compounds of Boron- Preparations, Properties & Uses |
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Given below are two statements:

Statement I: Colourless cupric metaborate is reduced to cuprous metaborate in a luminous flame.
Statement II: Cuprous metaborate is obtained by heating boric anhydride and copper sulphate in a non-luminous flame.

In the light of the above statements, choose the most appropriate answer from the options given
below.

1. Statement I is true but Statement II is false

2. Both Statement I and Statement II are false

3. Statement I is false but Statement II is true

4. Both Statement I and Statement II are true

Subtopic:  Boron Family- Preparations, Properties & Uses |
Level 3: 35%-60%
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