Advertisements
Advertisements
Question
Explain the following:
Aluminium forms [AlF6]3– ion but boron does not form [BF6]3– ion.
Advertisements
Solution
Al has vacant d-orbitals and hence can expand its coordination number from 4 to 6 and hence forms octahedral [AlF6]3– ion in which Al undergoes sp3d2 hybridisation. In contrast, B does not have d-orbitals. Therefore, it can have a maximum coordination number of 4. Therefore, B forms [BF4]– (in which B is sp3-hybridised) but not [BF6]3–.
APPEARS IN
RELATED QUESTIONS
Write reactions to justify amphoteric nature of aluminium.
What happens when Borax is heated strongly.
What happens when Boric acid is added to water?
What happens when Aluminium is treated with dilute NaOH?
Give reason for Conc. HNO3 can be transported in aluminium container.
Give reasons: A mixture of dilute NaOH and aluminium pieces is used to open drain.
Give reasons: Aluminium alloys are used to make aircraft body.
Give reasons: Aluminium utensils should not be kept in water overnight.
Give reasons: Aluminium wire is used to make transmission cables.
When metal X is treated with sodium hydroxide, a white precipitate (A) is obtained, which is soluble in excess of NaOH to give soluble complex (B). Compound (A) is soluble in dilute HCl to form compound (C). The compound (A) when heated strongly gives (D), which is used to extract the metal. Identify (X), (A), (B), (C) and (D). Write suitable equations to support their identities.
The type of hybridisation of boron in diborane is ______.
Assertion (A): If aluminium atoms replace a few silicon atoms in three-dimensional network of silicon dioxide, the overall structure acquires a negative charge.
Reason (R): Aluminium is trivalent while silicon is tetravalent.
Account for the following observations:
AlCl3 is a Lewis acid
\[\ce{AlF3}\] is soluble in HF only in presence of KF. It is due to the formation of ______.
