Group 13 elements show certain patterns in their chemical conduct. Boron, the first element in this group, shows some specific properties that are completely different from its other members.
The reasons why Boron is different from the other members are,
Its smaller size
Higher electronegativity
Its ionization enthalpy is higher
d shell is absent in it
It can attain a maximum covalency of only 4 due to the absence of d orbital
Properties of Boron
Boron is a non-metal or a metalloid
Boron is a bad conductor of electricity
Boron is allotropic
It is available in crystalline and amorphous forms
Boron has higher boiling and melting points
Boron forms only covalent bonds
Boron oxides, as well as hydroxides, are acidic
It forms inert hydrides
While the other members of the Boron family have p orbital, it is absent in boron
Group 13 Elements
Elements in this group show a trend in their physical and chemical properties:-
They form covalent bonds with halogens to form chlorides, bromides, or iodides which are easily hydrolyzed with water
They usually form tetrahedral or octahedral structured compounds
These elements are metals whose metallic nature increases going down the group
Oxides of the group 13 elements are generally amphoteric in nature with the exception of boron which shows acidic nature
Being amphoteric, they react with bases but boron is an exception
These elements are reactive to acids but boron does not react with acids
Boron family members form both ionic and covalent bonds
Hydrides of group 13 elements
Generally, the hydrides of group 13 elements are polymeric in nature with their stability decreasing as they go down the group. Boron forms the most number of hydrides and shows some anomalous properties.
Boron hydrides are volatile in nature and are called boranes. There are other boron hydrides with sodium and aluminium ( NaBH₄ and Al(BH₄)₃) that form an octet to form stable compounds, It is because of the presence of tetrahydroborate ion- BH₄.
Lithium boron hydride is a boron hydride which is significant as a reducing agent for aldehydes, esters, etc.
Anomalous Properties of Boron Hydrides
Boron hydrides are isolated only through the Lewis acid-base complex method
Diborane is formed in the balance of a Lewis base
Diborane is spontaneously flammable and is highly exothermic
Sodium borohydride is more stable and is present in crystalline form
Borohydride anion is less reactive than other hydrides of group 13 elements
The volatile boron hydrides are easily hydrolyzed and can burn instantly in presence of oxygen
Profile
Settings
Refer your friends
Sign out
