Number of possible alkynes with formula C₅H₈ is

• 2

• 3

• 4

• 5

On heating potassium permanganate, one of the following compound is not obtained.

• O₂

• MnO

• MnO₂

• K₂MnO₄

Which of the following compound possesses the C-H bond with the lowest bond dissociation energy?

• Toluene

• Benzene

• n-pentane

• 2, 2-dimethyl propane

In the presence of HCl, H₂S results the precipitation of group-2 elements but no group-4 elements during qualitative analysis. It is due to

• higher concentration of S^2-

• higher concentration of H⁺

• Lower concentration of S^2-

• Lower concentration of H⁺

Water softening by Clark's process uses

• CaHCO₂

• NaHCO₃

• Na₂CO₃

• Ca(OH)₂

An alkali metal hydride (NaH) reacts with diborane in. A to give a tetrahedral compound B which is extensively used as reducing agent in organic synthesis. The compounds A and B respectively are

• C₂H₆ and C₂H₅Na

• CH₃COCH₃ and B₃N₃H₆

• C₆H₆ and NaBH₄

• (C₂H₅)₂O and NaBH₄

The correct statement is

• BF₃ is the strongest Lewis acid among the other boron halides

• BI₃ is the weakest Lewis acid among the other boron halides

• there is maximum pπ- pπ back boinding in BF₃

• there is minimum pπ- pπ back boinding in BF₃

The arrangement of following compounds.

(i) Bromomethane

(ii) Bromoform

(iii) Chloromethane

(iv) Dibromomethane

In the increasing order of their boiling point is

• III < I < IV < II

• IV < III < I < IV

• II < III < I < IV

• I < II < III < IV

19.

The unit cell with crystallographic dimensions, a≠b≠c,α=γ=90 and β≠ 90 is

• triclinic

• monoclinic

• orthorhombic

• tetragonal

While charging the lead storage battery,

• PbSO₄ on anode is reduced to Pb

• PbSO₄ on cathode is reduced to Pb

• PbSO₄ on cathode is oxidised to Pb

• PbSO₄ on anode is oxidised to PbO₂