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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: shalikadm on February 07, 2013, 12:02:30 AM

Title: Oxidizing Chlorides
Post by: shalikadm on February 07, 2013, 12:02:30 AM

A book states like this:
CO₃^-,MnO₄^-.CrO₄^2-,Cr₂O₇₄^2-,HNO₃,ClO₃^-,ClO₄^- can oxidize Cl^- to Cl₂.

I have this questions in my mind:

• I haven't read about this CO₃^- thing anywhere.I think it's a printing mistake..Am I correct ?
  What will be the most suitable correct one for this ?
• Do we have to use HCl ? Can't we use something like KCl instead ..both have Cl^-,isn't it?
• Can we use KClO₄ instead of HClO₄?...As in KMnO₄...I feel that though HNO₃ do the thing,but KNO₃ doesn't.

Someone please explain these things to me..thanks !

Title: Re: Oxidizing Chlorides
Post by: Borek on February 07, 2013, 04:38:43 AM

No idea about this CO₃^- thing. Perhaps they meant half of the peroxodicarbonate.

Oxyacids are more effective as oxidizing agents in low pH, so you want H⁺ to be there.

Title: Re: Oxidizing Chlorides
Post by: shalikadm on February 07, 2013, 07:08:22 PM

My second thought,
I think that we can't use an oxidizing agent if we want cl₂ from KCl...we need the stronger oxidizing method, electrolysis to get Cl₂ out of the salt...but we can use an oxidizing agent with HCl to gain Cl₂..Am I correct ?
Thanks !

Title: Re: Oxidizing Chlorides
Post by: shalikadm on February 08, 2013, 08:48:37 AM

Quote from: shalikadm on February 07, 2013, 07:08:22 PM

My second thought,
I think that we can't use an oxidizing agent if we want cl₂ from KCl...we need the stronger oxidizing method, electrolysis to get Cl₂ out of the salt...but we can use an oxidizing agent with HCl to gain Cl₂..Am I correct ?
Thanks !

Sorry for my above post....molten KCl was in mind....
Just take an aqueous solution of K⁺Cl ^-...Can we yield Cl₂ using one of the oxidizers mentioned above ?
Another one....Let's think I have an aqueous solution of FeCl₂...Do we yield Cl₂ and Fe³⁺,when oxidized ?

Title: Re: Oxidizing Chlorides
Post by: shalikadm on February 13, 2013, 06:57:59 AM

any idea ?

Title: Re: Oxidizing Chlorides
Post by: ajkoer on February 26, 2013, 11:35:41 PM

Here is a possible example of a carbonate in a two step reaction resulting in the oxidation of HCl to Cl2:

(H2CO3 + NaOCl) + HCl -->  (NaHCO3 + HOCl) + HCl --> NaHCO3 + H2O + Cl2 --> NaCl + H2O + CO2 + HOCl....

The action of Carbonic acid on NaOCl is slow forming Hypochlorous acid. In the presence of HCl:

 HCl + HOCl <---> Cl2 + H2O

It is actually a path to form Hpochlorous acid to place Sodium carbonate or hydrogen carbonate (or the Metal hydroxide or the Metal oxide) in Chlorine water, thereby neutralizing the highly ionic HCl and leaving HOCl.
 

Title: Re: Oxidizing Chlorides
Post by: Borek on February 27, 2013, 03:39:56 AM

I would not say it is oxidation with carbonic acid - it is oxidation with hypochloric acid.

Title: Re: Oxidizing Chlorides
Post by: 408 on February 27, 2013, 07:14:55 AM

Quote from: shalikadm on February 07, 2013, 12:02:30 AM

• Do we have to use HCl ? Can't we use something like KCl instead ..both have Cl^-,isn't it?
• Can we use KClO₄ instead of HClO₄?...As in KMnO₄...I feel that though HNO₃ do the thing,but KNO₃ doesn't.

Aqueous perchlorate is a shitty oxidizing agent.  it will not oxidize chloride to chlorine.