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Showing posts with label Hydrolysis reactions (Inorg). Show all posts
Showing posts with label Hydrolysis reactions (Inorg). Show all posts

Tuesday, February 16, 2021

NCl3 and PCl3 on hydrolysis give different kinds of products. These is because of

(A) Attack of lone pair of water takes place to N and P respectively.

(B) Attack of lone pair of water takes place to Cl and Cl respectively.

(C) Attack of lone pair of water takes place to Cl and P respectively.

(D) None of these

Solution: (C) Their is no vacant d- orbitals hence attack of lone pair of water takes place to Cl and P respectively.

Related Questions:

Question(1): Why aqueous solution of AlCl3 is acidic in nature ?

Question(2): What happen when aq AlCl3 react with Acid or Base?

Question(3): Although anhydrous aluminium chloride is covalent but its aqueous solution is ionic in nature. Why?

Question(4): Arrange in increasing order of extent of hydrolysis [ CCI4, MgCI2, AICI3, PCl5, SiCI4].

Question(5): Although Sulphur contain vacant d-orbital but SF6 does not undergo hydrolysis. Why ?

Question(6): CCl4 can not be hydrolysed but SiCl4 can be. Why?

Question(7): What are the hydrolysis products of urea ?

Question(8): Why SF6 is inert where as SF4 is highly reactive towards H20 ?.

Question(9): Why SF6 behave inert towards hydrolysis?

Question(10): Why PCl3 hydrolysed while NCl3 can not be hydrolysed?

Question(11): Why hydrolysis of NCl3 gives NH4OH and HOCl, while PCl3 on hydrolysis gives H3PO3 and HCl?

Why hydrolysis of NCl3 gives NH4OH and HOCl, while PCl3 on hydrolysis gives H3PO3 and HCl?

 The hydrolysis of PCl3 may be contrasted with that of NCl3 this difference is due to the change in polarity of P-Cl bond in PCl3 in contrast to N-Cl bond in NCl3.



PF3 is not sensetive to H2O due to strong P-F bond F being more electronegative  than oxygen forms a strong covalent bond with p in coparison with P-O bond.

Related Questions:

Question(1): Why aqueous solution of AlCl3 is acidic in nature ?

Question(2): What happen when aq AlCl3 react with Acid or Base?

Question(3): Although anhydrous aluminium chloride is covalent but its aqueous solution is ionic in nature. Why?

Question(4): Arrange in increasing order of extent of hydrolysis [ CCI4, MgCI2, AICI3, PCl5, SiCI4].

Question(5): Although Sulphur contain vacant d-orbital but SF6 does not undergo hydrolysis. Why ?

Question(6): CCl4 can not be hydrolysed but SiCl4 can be. Why?

Question(7): What are the hydrolysis products of urea ?

Question(8): Why SF6 is inert where as SF4 is highly reactive towards H20 ?.

Question(9): Why SF6 behave inert towards hydrolysis?

Question(10): Why PCl3 hydrolysed while NCl3 can not be hydrolysed?

Thursday, January 28, 2021

Hydrolysis reactions (Inorganic reactions):

Hydrolysis is  a chemical process in which  a certain molecule is split into two parts by the addition of a molecule of water. One fragment of the parent molecule gains a hydrogen ion (H+) from the addition of water. The other group collects the remaining hydroxyl group(OH-) for examples :

(1) During  hydrolysis of a covalent compound having non metal central atom, if water molecule attack at central atom and hydrolysis occurs at room temperature then oxy acid of the non metal will be formed, if the central atom is in it one of the common oxidation state.  Oxidation state of  central atom of the oxy acid  will be same as its in the given substrate, However this rule is not applicable to XeF2, XeF4 and XeF3.

(2) hydrolysis reactions occur in non redox reaction except XeF2 and XeF4 and  mixed anhydride i.e. central atoms has its uncommon oxidation state for examples;

(3) During  hydrolysis, hybridization of central atom in transition state and may  or may not change.

(4) BF3, SiF4, CCl4, SbCl3, and BiCl3 undergo partial hydrolysis even in excess of water while PCl5, SF4, SeF6,IF7, XeF6 H4P2O8, H2S2O8,P4O10 can undergo partial as well as complete hydrolysis by adjusting the amount water.

(5) Rate of hydrolysis is directly proportional to the positive (+) charge density at least electronegative atoms of  substrate provided. And  the least electronegative  atom must contain vacant  orbital and have no crowding.The order of  rate of hydrolysis of some compounds are given as;

PCl5(V) > SiCl4(IV) > AlCl3(III) > MgCl2(II) > CCl4 (NO vacant orbital) > SF6 (Crowding)

Related Questions:

Question (1): Why aqueous solution of AlCl3 is acidic in nature?

Question (2): What happen when aq AlCl3 react with Acid or Base?

Question (3): Although anhydrous aluminium chloride is covalent but its aqueous solution is ionic in nature. Why?

Question (4): Arrange in increasing order of extent of hydrolysis [ CCI4, MgCI2, AICI3, PCl5, SiCI4].

Question (5): Although Sulphur contain vacant d-orbital but SF6 does not undergo hydrolysis. Why?

Question (6): CCl4 can not be hydrolysed but SiCl4 can be. Why?

Question (7): What are the hydrolysis products of urea?

Question (8): Why SF6 is inert where as SF4 is highly reactive towards H20?.

Question (9): Why SF6 behaves inert towards hydrolysis?

Question (10): Why PCl3 hydrolysed while NCl3 can not be hydrolysed?

Question (11): Why hydrolysis of NCl3 gives NH4OH and HOCl, while PCl3 on hydrolysis gives H3PO3 and HCl?

Question (12) NCl3 and PCl3 on hydrolysis give different kinds of products. These is because of


Saturday, January 2, 2021

Why aqueous solution of AlCl3 is acidic in nature ?

Aluminium forms covalent compound with chloride because lionization enthalpy (∆iH= +5137 kJ/mole) of Aluminium is very high due to small size and chlorine is unable to convert  Al into Al+3 ions. 

However, when anhydrous AlCl3 (which is covalent in character) is dissolved in water, it undergoes hydration as follow:  

AI2CI6 + H2O -->2[Al(H2O)6]+3 +(∆H)  

Hydration of anhydrous Aluminium chloride is highly exothermic in nature. The hydration enthalpy is more than ionisation enthalpy of aluminium.This hydration enthalpy removes all the three valence electrons of the aluminium leading to the formation of Al3+ more easly.This AI3+ is hydrated with water and form a complex ion. Thus in water Al exist as [Al(H2O)6]+3. so aqueous AlCl3 form Hexahydrated complex salt.

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?


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.

This complex ion behaves as an acid in water, losing protons, and a series of equilibria are established (H+ is used, rather than H3O+for simplicity):

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?

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:






Thursday, November 12, 2020

What is hydrolysis products of "Marshall's acid ?

Chemically "Marshall's acid" is Diperxosulphuric acid. The hydrolysis of one mole Marshall's acid required two mole water molecules and two moles sulphuric acid and one mole (H2O2) hydrogen peroxide (2:1) obtained, and this hydrolysis followed addition-Elimination mechanism.

What is hydrolysis products of "Caro's" acid ?

H2SO5 (Per sulphuric acid) is also know as Caro's acid and on hydrolysis gives sulphuric acid and Hydrogen peroxide. And this hydrolysis take place through addition-Elimination mechanism.

Saturday, November 7, 2020

Why halogens are insoluble in water ?

Halogens (X2) are "non polar" in nature , they are insoluble in water (polar solvent) but in soluble in non polar solvents  like CCl4, C6H6, and CS2 etc.
(1): But Fluorine is soluble in water due to its high oxidizing nature, decomposition even water and form ozonides oxygen.
(2): To increase the solubility of Iodine in water, potassium iodide (KI) is added


Monday, October 5, 2020

Why does SiCl4 undergo hydrolysis whereas CCl4 doesn't?

Their is mainly two reason that's why  SiCl4 undergo hydrolysis while CCl4 Not .
First is steric hindrance , in case CCl4 Cl atoms  blocking the C atom and preventing water molecules (nucleophile) from attacking it easily. While in case SiCl4 , Si is larger than C so  there is less crowding so it is more susceptible to attack by the (water molecules) nucleophile.
Second reason is presence of vacant d orbital. Thus, Water, acting as nucleophile can attack easily at the vacant d orbital of Si and reaction will occur through penta co-ordinated transition state.But  in case of CCl4 due to the absence of d orbital and smaller size of carbon makes ligand environment more crowded and nucleophile can't easily attack to the central atom.
 

Sunday, February 9, 2020

Why SF6 is inert where as SF4 is highly reactive towards H20 ?.


The maximum coordination number of sulphur is 6. Hence S cannot accommodate more than 12 electrons around it. SF6 is covalently saturated compound. Thus six fluorine atoms around sulphur protect sulphur from attack by reagent to such an extent that even thermodynamically favorable reaction like hydrolysis (S-O bond is stronger than S-F bond) does not occur. On the other hand, in SF4, the coordination number is only four. Hence sulphur can be attacked by H2O.


Related Questions:

Question (1): Why aqueous solution of AlCl3 is acidic in nature?

Question (2): What happen when aq AlCl3 react with Acid or Base?

Question (3): Although anhydrous aluminium chloride is covalent but its aqueous solution is ionic in nature. Why?

Question (4): Arrange in increasing order of extent of hydrolysis [ CCI4, MgCI2, AICI3, PCl5, SiCI4].

Question (5): Although Sulphur contain vacant d-orbital but SF6 does not undergo hydrolysis. Why?

Question (6): CCl4 can not be hydrolysed but SiCl4 can be. Why?

Question (7): What are the hydrolysis products of urea?

Question (8): Why SF6 is inert where as SF4 is highly reactive towards H20?.

Question (9): Why SF6 behaves inert towards hydrolysis?

Question (10): Why PCl3 hydrolysed while NCl3 can not be hydrolysed?

Question (11): Why hydrolysis of NCl3 gives NH4OH and HOCl, while PCl3 on hydrolysis gives H3PO3 and HCl?

Question (12) NCl3 and PCl3 on hydrolysis give different kinds of products. These is because of