Gr-13 elements

Which is true for an element R present in group 13 of period table

• It is a gas at room temperature

• It has oxidation state of +4

• It form R₂O₃

• It forms RX₂

Which member of group 13 does not exhibit the group valency in its compounds

• B

• Al

• Tl

• In

Which one of the following is a correct statement

• Al is more acidic than that of B

• B is basic while that of Al is amphoteric

• B is acidic while that of Al is amphoteric

• Al are amphoteric

Thallium shows different oxidation states because

• It is transition element

• Of inert pair effect

• Of its amphoteric character

• Of its higher reactivity

Which of the following statements about H₃BO₃ is not correct

• It is a strong tribasic acid

• It is prepared by acidifying an aqueous solution of borax

• It has a layer structure in which planar BO₃ units are joined by hydrogen bonds

• It does not act as proton donor but acts as a Lewis acid by accepting hydroxyl ion

The type of hybridisation of boron in diborane is

• sp

• sp²

• sp³

• sp³d²

Identify the statement that is not correct as far as structure of diborane is concerned

• There are two bridging hydrogen atoms in diborane

• Each boron atom forms four bonds in diborane

• The hydrogen atoms are not in the same plane in diborane

• All B - H bonds in diborane are similar

Which of the following is most acidic

• Na₂O

• MgO

• Al₂O₃

• CaO

When orthoboric acid (H₃BO₃) is heated, the residue left is

• Metaboric acid

• Boron

• Boric anhydride

• Borax

Which of the following is known as inorganic benzene

• Borazine

• Boron nitride

• p-dichlorobenzene

• Phosphonitrilic acid