Sunday, December 27, 2020
What happen when aq AlCl3 react with Acid or Base?
When a soluble aluminium salt is placed in water at room temperature. Initially the aluminium ion is surrounded by six water molecules and the complex ion has the predicted octahedral Geometry.
These equilibria give rise to an acidic solution in water, to the Hexahydroxoaluminate(iii) ion [Al(OH)6]3- in a strongly alkaline solution, and only in strongly acidic solutions is the hexaaquo ion [Al(H2O)6]3+ found.
The solid
hydrate, often written AlCl3. 6H2O and more correctly [Al(H2O)6]Cl3 can, therefore,
only be obtained from a strongly acidic solution. The reaction with water
resulting in the liberation of a proton is again known as hydrolysis and occurs whenever the
central metal ion is small and highly charged (i.e. having a high surface
density of charge), for example in salts of iron(III), chrornium(III).
Related
Questions:
(1) Although anhydrous aluminium chloride is covalent but its aqueous solution is ionic in nature. Why?
(2) Why Ga has small size than Al exceptionally
(3) Why aqueous solution of borax reacts with two moles of acids ?
(4) What is structure of solid Ortho Boric acid ?
(5) What is the structure of trimetaboric acid and trimetaborate ion?
(6) Why Borazine is more reactive than benzene towards Electrophic Aromatic substitution reactions ?
(7) Why Borazine (B3N3H6) is also known as inorganic benzene ?.
(8) Why B-F bond length in BF3 is shorter (130 pm) than B-F bond Iength in BF4- (143 pm)?. Explain.
(9) Why B-F do not exist as dimer?. Explain.
(10) Although anhydrous aluminium chloride is covalent but its aqueous solution is ionic in nature. Why?
(11) Why Boric acid become strong acid in the presence of cis 1,2-diol or 1,3-diol ?
(12) Four-center two-electron bond (4C-2e Bond): Structure of AlCl3:
(13) What is the molecular formula of Borax ?
(14) What is the difference between the structure of AlCl3 and diborane?
What is the structure of Melamine and how can synthesied ?
Melamine formed by trimerization of H2N– CN ( cyanamide ). Which is also known as cyanuric amide.
Why SF6 is inert while SF4 is a very reactive molecule that reacts with H2O rapidly and vigorously?
The fact that SF6
does not react with water is not due to thermodynamic stability. Rather, it is
because there is no low-energy pathway for the reaction to take place (kinetic stability).
Six fluorine atoms surrounding the sulfur atom
effectively prevent attack of water molecules and the sulfur atom has no
unshared pairs of electrons where other molecules might attack. In SF4
, not only is there sufficient space for an attacking species (water) to gain
access to the sulfur atom, but also the unshared pair is a reactive site. As a
result of these structural differences, SF6 is relatively inert,
whereas SF4 is very reactive.
Related Questions:
(7) Arrange the silicon halides into decreasing order of Lewis acids Character? SiF4, SiCl4, SiBr4, SiI4
Why is BCl3 a strongerLewis acid than BF3 ?
The strength of a Lewis acid is a measure of its ability to attract a pair of electrons on a molecule that is behaving as a Lewis base. Fluorine is more electronegative than chlorine, so it appears that three fluorine atoms should withdraw electron density from the boron atom, leaving it more positive.This would also happen to some extent when the peripheral atoms are chlorine, but chlorine is less electronegative than fluorine. On this basis, we would expect BF3 to be a stronger Lewis acid. However,in the BF3 molecule, the boron atom uses sp2 hybrid orbitals, which leaves one empty 2p orbital that is perpendicular to the plane of the molecule. The fluorine atoms have filled 2p orbitals that can overlap with the empty 2p orbital on the boron atom to give some double bond character (Back Bond) to the B–F bonds.
As a result of the contribution by resonance structures having some double bond character, the boron atom in BF3 is not as electron deficient as it is in BCl3. And hence BCl3 a stronger Lewis acid than BF3
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