Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  ..  5    7
Author: Subject: PbO2
SAM4CH
Hazard to Others
***




Posts: 162
Registered: 16-7-2004
Location: TA
Member Is Offline

Mood: PERFECT

[*] posted on 11-12-2005 at 13:55


What about Silver for using as anode for plating Lead Dioxide from Pb-Cu/Nitrate solution!??



Sam
View user's profile View All Posts By User This user has MSN Messenger
12AX7
Post Harlot
*****




Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline

Mood: informative

[*] posted on 11-12-2005 at 16:04


Sure? I don't see why not, since it gets covered immediately.. after a moment your anode surface becomes PbO2 plating on PbO2... LOL

Actually using it is different matter, bad things probably happen... although in a chloride electrolyte, insoluble AgCl would form, no?

Tim




Seven Transistor Labs LLC http://seventransistorlabs.com/
Electronic Design, from Concept to Layout.
Need engineering assistance? Drop me a message!
View user's profile Visit user's homepage View All Posts By User This user has MSN Messenger
SAM4CH
Hazard to Others
***




Posts: 162
Registered: 16-7-2004
Location: TA
Member Is Offline

Mood: PERFECT

[*] posted on 12-12-2005 at 14:12


I perpared solution but it is no PbO2 on Silver anode!!? the solution became slightly colloidal with white color!!



Sam
View user's profile View All Posts By User This user has MSN Messenger
12AX7
Post Harlot
*****




Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline

Mood: informative

[*] posted on 4-5-2006 at 18:17
Oxidizing PbO2


I'm thinking about Mn(III) and (IV) tonight. I wonder is there any reasonable way you could oxidize Pb(II) with them? Mn is a pretty strong oxidizer, though I'll have to check since Pb(IV) is pretty strong itself.

How would the reaction proceed? Both make brown oxidized smudge. Mn(III) is sort of soluble in acid (very burgundy :) ), but it seems to hydrolyze like nuts. Plus, it would take nitric to allow Pb(II) ions in solution (unless PbSO4 ppt can be oxidized). Hydrochloric acid would be long ago oxidized by either product, so that's no good.

Tim




Seven Transistor Labs LLC http://seventransistorlabs.com/
Electronic Design, from Concept to Layout.
Need engineering assistance? Drop me a message!
View user's profile Visit user's homepage View All Posts By User This user has MSN Messenger
kazaa81
National Hazard
****




Posts: 368
Registered: 30-4-2004
Member Is Offline

Mood: ok

[*] posted on 6-5-2006 at 17:12


Can one reduce the sodium plumbate (produced by fusing NaOH with metallic Pb) to a lead-only salt (without sodium)?

Thanks
View user's profile View All Posts By User
12AX7
Post Harlot
*****




Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline

Mood: informative

[*] posted on 6-5-2006 at 19:13


Quote:
Originally posted by kazaa81
Can one reduce the sodium plumbate (produced by fusing NaOH with metallic Pb) to a lead-only salt (without sodium)?

Thanks


Er, wasn't it posted earlier that Pb basically doesn't respond to alkali?

Anyways, do you mean the acid ion (plumbic/plumbous) or anhydride (which would just be the oxide), or a lead salt of the lead anion (i.e., plumbous (II) plumbate (IV), otherwise known as, get this, Pb3O4)?

I'm sure adding HNO3 to drop the pH will free plenty of the acid component, as with any insoluble acid compound (borate, etc.).

Tim




Seven Transistor Labs LLC http://seventransistorlabs.com/
Electronic Design, from Concept to Layout.
Need engineering assistance? Drop me a message!
View user's profile Visit user's homepage View All Posts By User This user has MSN Messenger
12AX7
Post Harlot
*****




Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline

Mood: informative

[*] posted on 6-5-2006 at 23:37


Quote:
Originally posted by BromicAcid
Then take your lead salt and add the hydroxide of your choosing, like NaOH to precipitate the lead hydroxide. Take the lead hydroxide and add a hypochlorite like Ca(OCl)2 or possibly NaOCl and your lead dioxide will precipitate out.


Seems to work well- I grabbed some crude PbCl2, neutralized what acid was left as well as the salt with some NaHCO3 (hmm, I'm out of it), added Ca(OCl)2 flakeybits, hmm turning color good, yellow, drab ugly brown, eventually to a "vivid" brown. Oh noes, I smell chlorine.. better...um... I know, limestone gravel!

And that's where I've left the experiment for the night. Tomorrow I'll see how the product looks and compare it to other PbO2 I've collected (mostly electrolytically).

Edit: looks good. Got less than I expected, but reasonable I suppose. Solution was still acidic (*cough* chloriney) despite the gravel, oh well. Color is comparable to my electrolytic PbO2, but cleaner. :D A lot like clay, but still filtered reasonably- a lot of fine particles still got through though.
/Edit

In other news, my PbO junk is ever so slowly dissolving in vinegar. It's weak ass, but cheap, 4% stuff. I dropped half a pound of PbO to a gallon of the stuff (~4L), which should be about right. I also added what PbAc2 I made a long time ago, all contaminated with probably Fe. The vinegar solution is now brown. :rolleyes: Question: what's the azeotrope for acetic acid, and is it affected by the salt present? ISTR it's something low in acid (3%?), which is dangerously close to all my acid evaporating from solution. That doesn't make sense to me since GAA is hard to make.

Tim

[Edited on 5-7-2006 by 12AX7]




Seven Transistor Labs LLC http://seventransistorlabs.com/
Electronic Design, from Concept to Layout.
Need engineering assistance? Drop me a message!
View user's profile Visit user's homepage View All Posts By User This user has MSN Messenger
quest
Hazard to Self
**




Posts: 75
Registered: 15-9-2003
Member Is Offline

Mood: No Mood

[*] posted on 23-2-2007 at 05:06
My try with PbO2 electrode


Hi guys,
I tried making pure PbO2 electrode today.
I used 2 shits of Al 3 m"m thick and used electrolysis in PbNO3/CuNO3 solution.
The current was 1.05 A and the voltage about 2 V. I warmed the solution to 55 C.
After an hour I came to see if this worked and found that my anode has corroded a little and on my cathode I got very thick Cu coating.
the anode look a little gray but this isn't coating, I tried scraping the gray coat and it just don't scrap.
*The anode became less thick too.

is there any reason for not using Al electrodes in this experiment?

anode:


catohde:


the cell:


[Edited on 23-2-2007 by quest]
View user's profile View All Posts By User
12AX7
Post Harlot
*****




Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline

Mood: informative

[*] posted on 23-2-2007 at 10:00


Obviously, aluminum is NOT a suitable substrate. Seems obvious to me given its reactivity (especially with copper in solution, especially as the anode).

Tim




Seven Transistor Labs LLC http://seventransistorlabs.com/
Electronic Design, from Concept to Layout.
Need engineering assistance? Drop me a message!
View user's profile Visit user's homepage View All Posts By User This user has MSN Messenger
 Pages:  1  ..  5    7

  Go To Top