Chemistry Question Bank

Na2B4O7.10H2O is correctly represented as:

Which of the following is not true regarding the nature of halides of boron ?

Which of the following is a false statement ?

The power of halides of boron to act as Lewis acids decreases in the order:

The main factor responsible for weak acidic nature of B—F bonds in BF3 is:

BCl3 does not exist as a dimer but BH3 exists as B2H6 because

In B2H6:

The structure of diborane (B2H6) contains :

In diborane, the two H – B – H angles are nearly :

The type of hybridization of boron in diborane is

In diborane,

On hydroloysis, diborane produces

Boric acid has a polymeric layer structure in which planar BO3 units are joined by

Boric acid is prepared from borax by the action of :

An aqueous solution of boric acid is found to be weakly acidic in nature. This acidic character arises due to the following reasons.

H3BO3 is:

Boric acid H3BO3 and BF3 have the same number of elec- trons. The former is a solid and the latter is a gas. The reason is:

What happens when a mixture of cobalt oxide and borax is heated in a flame on a loop of platinum wire ?

Borax bead test is responded by:

The number of OH units directly linked to boron atoms in Na2B4O7.10H2O is:

Na B O .10H O Na B O X NaBO B O Y z D ¾¾® ¯ D + 39. (S) Borax is used as a cleansing agent because on dissolv- ing in water, it gives:

Na B O .10H O X Y Z D D ¾¾® ¾¾® + X, Y and Z in the reaction are (a) X Na B O , Y NaBO , Z B O = = = (b) X Na B O , Y B O , Z H BO = = = (c) X B O , Y NaBO , Z B(OH) = = = (d) X NaBO , Y B O , Z B(OH) = = =

On the addition of mineral acid to an aqueous solution of borax, the following compound is formed:

The geometry of a complex species can be understood from the knowledge of type of hybridisation of orbitals of central atom. The hybridisation of orbitals of central atom in [B(OH)4]– and the geometry of the complex a…

Which of the following compounds are formed when BCl3 is treated with water ?