pKa of H3PO4 is 7.2 x 10-3 and pKa of acetic acid is 1.76x10-5 .
So main point is we need to stop the dissolution of Manganese Phosphate in water , if we use strong acid it will get dissloved and get further oxidized . Thats why we are using Acetic acid ?? Let suppose if we use KMO4 with HCl in non stoichiometric amount then what will happen ?? Our KMnO4 will get wasted ?? As it will oxidise Cl- first to Cl2 ?? And Hypochlorite will prevent this wastage ?? Even Hypochlorite can oxidise the Chloride .!!
Nd I didn't get Why Mn(H2PO4)2 is the best reagent ??
Sorry for asking such questions....I am very bad in inorganic
pKa of H3PO4 is 7.2 x 10-3 and pKa of acetic acid is 1.76x10-5 .
So main point is we need to stop the dissolution of Manganese Phosphate in water , if we use strong acid it will get dissloved and get further oxidized . Thats why we are using Acetic acid ?? Let suppose if we use KMO4 with HCl in non stoichiometric amount then what will happen ?? Our KMnO4 will get wasted ?? As it will oxidise Cl- first to Cl2 ?? And Hypochlorite will prevent this wastage ?? Even Hypochlorite can oxidise the Chloride .!!
Nd I didn't get Why Mn(H2PO4)2 is the best reagent ??
Sorry for asking such questions....I am very bad in inorganic
Compare strength of acetic acid, H3PO4, and HCl or HNO3 or H2SO4. MnPO4 is formed even without strong oxidizer - oxygen from air is sufficent but you need mixing about 2 weeks. In this case you need manganese acetate and phosphoric acid. There is also method that use nitric acid as oxidizer. There are 2 hydrates of MnPO4: mineral serrabrancaite - monohydrate (serrabrancaite (was synthesized by oxidizing Mn(H2PO4)2 with NaClO solution in 2010) and synthetic sesquihydrate.
You quote from Greenwood concern manganese acetate complex, not phospate. There is also information that Mn(III) is stabilized by O-donors.
Compare strength of acetic acid, H3PO4, and HCl or HNO3 or H2SO4. MnPO4 is formed even without strong oxidizer - oxygen from air is sufficent but you need mixing about 2 weeks. In this case you need manganese acetate and phosphoric acid. There is also method that use nitric acid as oxidizer. There are 2 hydrates of MnPO4: mineral serrabrancaite - monohydrate (serrabrancaite (was synthesized by oxidizing Mn(H2PO4)2 with NaClO solution in 2010) and synthetic sesquihydrate.
You quote from Greenwood concern manganese acetate complex, not phospate. There is also information that Mn(III) is stabilized by O-donors.
Searching carefully internet you can find at least three methods of synthesis. Then you should find journals in your library, or find them through library access to journals from your library. Below you find an abstract from Elsevier Journal (hypochlorite oxidation) http://www.sciencedirect.com/science/article/pii/S129325581000066X This abstract is in public domain and for wise chemist is sufficient for repeating this synthesis.
Searching carefully internet you can find at least three methods of synthesis. Then you should find journals in your library, or find them through library access to journals from your library. Below you find an abstract from Elsevier Journal (hypochlorite oxidation) http://www.sciencedirect.com/science/article/pii/S129325581000066X This abstract is in public domain and for wise chemist is sufficient for repeating this synthesis.
pKa of H3PO4 is 7.2 x 10-3 and pKa of acetic acid is 1.76x10-5 .
pKa2 ?
Quote
So main point is we need to stop the dissolution of Manganese Phosphate in water , if we use strong acid it will get dissloved and get further oxidized . Thats why we are using Acetic acid ??
Manganese phosphate does not dissolve in water and acetic acid.
Quote
Let suppose if we use KMO4 with HCl in non stoichiometric amount then what will happen ?? Our KMnO4 will get wasted ?? As it will oxidise Cl- first to Cl2 ??
Do you prefer danger (Cl2) and difficulties in isolation?
Quote
Even Hypochlorite can oxidise the Chloride .!!
for chloride and hypochlorite ??
Quote
Nd I didn't get Why Mn(H2PO4)2 is the best reagent ??
This is the experience of chemists showed in publications that you should read. Your procedure also use it.
Quote
Q.2 I prepared it from dissolving MnSO4 and (NH4)2HPO4 , adding pure acetic acid
Acetic acid converts hydrogen phosphate anion into dihydrogen phosphate anion. Coordinated Mn(II) is oxidized to Mn(III) and the manganese(III) phosphate is formed. This pH (acetic acid) prevents precipitation of Mn3(PO4)2.
pKa of H3PO4 is 7.2 x 10-3 and pKa of acetic acid is 1.76x10-5 .
pKa2 ?
Quote
So main point is we need to stop the dissolution of Manganese Phosphate in water , if we use strong acid it will get dissloved and get further oxidized . Thats why we are using Acetic acid ??
Manganese phosphate does not dissolve in water and acetic acid.
Quote
Let suppose if we use KMO4 with HCl in non stoichiometric amount then what will happen ?? Our KMnO4 will get wasted ?? As it will oxidise Cl- first to Cl2 ??
Do you prefer danger (Cl2) and difficulties in isolation?
Quote
Even Hypochlorite can oxidise the Chloride .!!
for chloride and hypochlorite ??
Quote
Nd I didn't get Why Mn(H2PO4)2 is the best reagent ??
This is the experience of chemists showed in publications that you should read. Your procedure also use it.
Quote
Q.2 I prepared it from dissolving MnSO4 and (NH4)2HPO4 , adding pure acetic acid
Acetic acid converts hydrogen phosphate anion into dihydrogen phosphate anion. Coordinated Mn(II) is oxidized to Mn(III) and the manganese(III) phosphate is formed. This pH (acetic acid) prevents precipitation of Mn3(PO4)2.
From where can i get those Journals or articles ??
I got that why we need acetic acid it s ka just in between ka2 and ka1 of phosphoric acid . And its the experimental fact that we need H2PO4- for smooth Oxidation .
Its all about pH , that means we can use propanoic acd or formic acid .??
From where can i get those Journals or articles ??
I got that why we need acetic acid it s ka just in between ka2 and ka1 of phosphoric acid . And its the experimental fact that we need H2PO4- for smooth Oxidation .
Its all about pH , that means we can use propanoic acd or formic acid .??
HCl cannot be used with KMnO4 but you may use stoichiometric amount of HCl with hypochlorite as oxidizer of Mn(II) acetate. Mn(H2PO4)2 is the best reagent for oxidation. For this purpose acetic acid is used (look at pKas of H3PO4). Strenght of oxidizer is not important when relatively stable in acidic medium Mn(III) is precipitaded as MnPO4. Dissolution of this compound in strong acid allows further oxidation of Mn(III). In oxidation with oxygen an additional equilibrium gas-liquid is involved, hence much more time is needed. Trivalent metal phosphates show rather small solubility products. This cause that they are insoluble in very diluted HNO3. So, theoretically, you can also use nitric acid as oxidizer with substantial loss of yield.
HCl cannot be used with KMnO4 but you may use stoichiometric amount of HCl with hypochlorite as oxidizer of Mn(II) acetate. Mn(H2PO4)2 is the best reagent for oxidation. For this purpose acetic acid is used (look at pKas of H3PO4). Strenght of oxidizer is not important when relatively stable in acidic medium Mn(III) is precipitaded as MnPO4. Dissolution of this compound in strong acid allows further oxidation of Mn(III). In oxidation with oxygen an additional equilibrium gas-liquid is involved, hence much more time is needed. Trivalent metal phosphates show rather small solubility products. This cause that they are insoluble in very diluted HNO3. So, theoretically, you can also use nitric acid as oxidizer with substantial loss of yield.
In some literature I've Found that HCl is better acid. Than H2SO4..!!!
Bdw Meanwhile I've found that Mn+3 is get stablized by Hard bases.... Acetate is also an Hard base so as PO43- . But I've not read about Soft-Hard Acid Base concept in detail , I know about it in nutshell , High charge density = Hard Base.. Since in Phosphate and Nitrate and Sulphate ion the unit charge is dispersed on More than one atom they are slightly softer base... ?? Acetic acid is harder than these ...!! It can be the reason why we only acetic acid ??
And In strong acidic medium the KMnO4 will become very strong Oxidizing agent , may be it will oxidise Mn+3 further to +4 or +5??
According to you we need mild Oxidizing agent since without it , reaction will be slow.....so we used KMnO4 , but I didn't get hy we used Acetic acid ??
Moreover I've quoted for acetate complex , I thought it is relevant because in solution when Mn+3 ions was forming intially they were getting stablized by Acetate then when they come in contact of Phosphate ion they get precipitate out from solution. Is there any problem in my thought ??
In some literature I've Found that HCl is better acid. Than H2SO4..!!!
Bdw Meanwhile I've found that Mn+3 is get stablized by Hard bases.... Acetate is also an Hard base so as PO43- . But I've not read about Soft-Hard Acid Base concept in detail , I know about it in nutshell , High charge density = Hard Base.. Since in Phosphate and Nitrate and Sulphate ion the unit charge is dispersed on More than one atom they are slightly softer base... ?? Acetic acid is harder than these ...!! It can be the reason why we only acetic acid ??
And In strong acidic medium the KMnO4 will become very strong Oxidizing agent , may be it will oxidise Mn+3 further to +4 or +5??
According to you we need mild Oxidizing agent since without it , reaction will be slow.....so we used KMnO4 , but I didn't get hy we used Acetic acid ??
Moreover I've quoted for acetate complex , I thought it is relevant because in solution when Mn+3 ions was forming intially they were getting stablized by Acetate then when they come in contact of Phosphate ion they get precipitate out from solution. Is there any problem in my thought ??
So main point is we need to stop the dissolution of Manganese Phosphate in water , if we use strong acid it will get dissloved and get further oxidized .
Thats why we are using Acetic acid ??
Let suppose if we use KMO4 with HCl in non stoichiometric amount then what will happen ??
Our KMnO4 will get wasted ?? As it will oxidise Cl- first to Cl2 ??
And Hypochlorite will prevent this wastage ?? Even Hypochlorite can oxidise the Chloride .!!
Nd I didn't get Why Mn(H2PO4)2 is the best reagent ??
Sorry for asking such questions....I am very bad in inorganic
So main point is we need to stop the dissolution of Manganese Phosphate in water , if we use strong acid it will get dissloved and get further oxidized .
Thats why we are using Acetic acid ??
Let suppose if we use KMO4 with HCl in non stoichiometric amount then what will happen ??
Our KMnO4 will get wasted ?? As it will oxidise Cl- first to Cl2 ??
And Hypochlorite will prevent this wastage ?? Even Hypochlorite can oxidise the Chloride .!!
Nd I didn't get Why Mn(H2PO4)2 is the best reagent ??
Sorry for asking such questions....I am very bad in inorganic
More
VOTE
MnPO4 is formed even without strong oxidizer - oxygen from air is sufficent but you need mixing about 2 weeks. In this case you need manganese acetate and phosphoric acid.
There is also method that use nitric acid as oxidizer.
There are 2 hydrates of MnPO4: mineral serrabrancaite - monohydrate (serrabrancaite (was synthesized by oxidizing Mn(H2PO4)2 with NaClO solution in 2010) and synthetic sesquihydrate.
You quote from Greenwood concern manganese acetate complex, not phospate. There is also information that Mn(III) is stabilized by O-donors.
MnPO4 is formed even without strong oxidizer - oxygen from air is sufficent but you need mixing about 2 weeks. In this case you need manganese acetate and phosphoric acid.
There is also method that use nitric acid as oxidizer.
There are 2 hydrates of MnPO4: mineral serrabrancaite - monohydrate (serrabrancaite (was synthesized by oxidizing Mn(H2PO4)2 with NaClO solution in 2010) and synthetic sesquihydrate.
You quote from Greenwood concern manganese acetate complex, not phospate. There is also information that Mn(III) is stabilized by O-donors.
More
VOTE
More
VOTE
Below you find an abstract from Elsevier Journal (hypochlorite oxidation)
http://www.sciencedirect.com/science/article/pii/S129325581000066X
This abstract is in public domain and for wise chemist is sufficient for repeating this synthesis.
Below you find an abstract from Elsevier Journal (hypochlorite oxidation)
http://www.sciencedirect.com/science/article/pii/S129325581000066X
This abstract is in public domain and for wise chemist is sufficient for repeating this synthesis.
More
VOTE
Quote
Manganese phosphate does not dissolve in water and acetic acid.
QuoteDo you prefer danger (Cl2) and difficulties in isolation?
Quotefor chloride and hypochlorite ??
QuoteThis is the experience of chemists showed in publications that you should read.
Your procedure also use it.
QuoteAcetic acid converts hydrogen phosphate anion into dihydrogen phosphate anion. Coordinated Mn(II) is oxidized to Mn(III) and the manganese(III) phosphate is formed. This pH (acetic acid) prevents precipitation of Mn3(PO4)2.
Quote
Manganese phosphate does not dissolve in water and acetic acid.
QuoteDo you prefer danger (Cl2) and difficulties in isolation?
Quotefor chloride and hypochlorite ??
QuoteThis is the experience of chemists showed in publications that you should read.
Your procedure also use it.
QuoteAcetic acid converts hydrogen phosphate anion into dihydrogen phosphate anion. Coordinated Mn(II) is oxidized to Mn(III) and the manganese(III) phosphate is formed. This pH (acetic acid) prevents precipitation of Mn3(PO4)2.
More
VOTE
I got that why we need acetic acid it s ka just in between ka2 and ka1 of phosphoric acid . And its the experimental fact that we need H2PO4- for smooth Oxidation .
Its all about pH , that means we can use propanoic acd or formic acid .??
I got that why we need acetic acid it s ka just in between ka2 and ka1 of phosphoric acid . And its the experimental fact that we need H2PO4- for smooth Oxidation .
Its all about pH , that means we can use propanoic acd or formic acid .??
More
VOTE
Mn(H2PO4)2 is the best reagent for oxidation. For this purpose acetic acid is used (look at pKas of H3PO4). Strenght of oxidizer is not important when relatively stable in acidic medium Mn(III) is precipitaded as MnPO4. Dissolution of this compound in strong acid allows further oxidation of Mn(III).
In oxidation with oxygen an additional equilibrium gas-liquid is involved, hence much more time is needed.
Trivalent metal phosphates show rather small solubility products. This cause that they are insoluble in very diluted HNO3. So, theoretically, you can also use nitric acid as oxidizer with substantial loss of yield.
Mn(H2PO4)2 is the best reagent for oxidation. For this purpose acetic acid is used (look at pKas of H3PO4). Strenght of oxidizer is not important when relatively stable in acidic medium Mn(III) is precipitaded as MnPO4. Dissolution of this compound in strong acid allows further oxidation of Mn(III).
In oxidation with oxygen an additional equilibrium gas-liquid is involved, hence much more time is needed.
Trivalent metal phosphates show rather small solubility products. This cause that they are insoluble in very diluted HNO3. So, theoretically, you can also use nitric acid as oxidizer with substantial loss of yield.
More
VOTE
In some literature I've Found that HCl is better acid. Than H2SO4..!!!
Bdw Meanwhile I've found that Mn+3 is get stablized by Hard bases.... Acetate is also an Hard base so as PO43- .
But I've not read about Soft-Hard Acid Base concept in detail , I know about it in nutshell , High charge density = Hard Base..
Since in Phosphate and Nitrate and Sulphate ion the unit charge is dispersed on More than one atom they are slightly softer base... ??
Acetic acid is harder than these ...!!
It can be the reason why we only acetic acid ??
And In strong acidic medium the KMnO4 will become very strong Oxidizing agent , may be it will oxidise Mn+3 further to +4 or +5??
According to you we need mild Oxidizing agent since without it , reaction will be slow.....so we used KMnO4 , but I didn't get hy we used Acetic acid ??
Moreover I've quoted for acetate complex , I thought it is relevant because in solution when Mn+3 ions was forming intially they were getting stablized by Acetate then when they come in contact of Phosphate ion they get precipitate out from solution. Is there any problem in my thought ??
In some literature I've Found that HCl is better acid. Than H2SO4..!!!
Bdw Meanwhile I've found that Mn+3 is get stablized by Hard bases.... Acetate is also an Hard base so as PO43- .
But I've not read about Soft-Hard Acid Base concept in detail , I know about it in nutshell , High charge density = Hard Base..
Since in Phosphate and Nitrate and Sulphate ion the unit charge is dispersed on More than one atom they are slightly softer base... ??
Acetic acid is harder than these ...!!
It can be the reason why we only acetic acid ??
And In strong acidic medium the KMnO4 will become very strong Oxidizing agent , may be it will oxidise Mn+3 further to +4 or +5??
According to you we need mild Oxidizing agent since without it , reaction will be slow.....so we used KMnO4 , but I didn't get hy we used Acetic acid ??
Moreover I've quoted for acetate complex , I thought it is relevant because in solution when Mn+3 ions was forming intially they were getting stablized by Acetate then when they come in contact of Phosphate ion they get precipitate out from solution. Is there any problem in my thought ??
More
VOTE