Electronic flash has corroded electrical contacts. Duracell AA
batteries leaked. The contacts are molded into a plastic holder and
cannot be easily removed. I have cleaned the metal contacts using a
diamond tip. I did this a few months ago and the contacts re-corroded.
Again cleaned but what can I do to retard corrosion? Some in place
coating or plating?



--- news://freenews.netfront.net/ - complaints: ---

"OldGuy" wrote in message ...
Electronic flash has corroded electrical contacts. Duracell AA
batteries leaked. The contacts are molded into a plastic holder and
cannot be easily removed. I have cleaned the metal contacts using a
diamond tip. I did this a few months ago and the contacts re-corroded.
Again cleaned but what can I do to retard corrosion? Some in place
coating or plating?



--- news://freenews.netfront.net/ - complaints: ---

They have an anti-corrosion spray for car battery terminals. Clean
the terminals via what is easiest, spray some of the anti-corrosion
on some q-tips and rub on contacts.

If possible remove all pits from contacts since this tends to enhance
corrosion regardless of treatment. Filling and shaping with solder
might be an option if damage to other parts of the device will not
occur. Tricky, so this might not be an option.

On Thu, 21 Nov 2013 19:57:17 -0800, OldGuy
wrote:

Electronic flash has corroded electrical contacts. Duracell AA
batteries leaked. The contacts are molded into a plastic holder and
cannot be easily removed. I have cleaned the metal contacts using a
diamond tip. I did this a few months ago and the contacts re-corroded.
Again cleaned but what can I do to retard corrosion? Some in place
coating or plating?

Copper contacts?

Grease. Any type that excludes oxygen and water. Keep those out and
the copper won't corrode. Yeah, it's messy, but how often do you
change the batteries?

Bright electroless tin will inhibit corrosion. You won't like the
price:
http://www.caswellplating.com/electroplating-anodizing/tin-plating-kits/electroless-tin-plating-kits.html
Hot tin plating is cheaper and better, but messy.
http://www.caswellplating.com/electroplating-anodizing/tin-plating-kits/tin-electroplating-kits.html

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

OldGuy wrote:
Electronic flash has corroded electrical contacts. Duracell AA
batteries leaked. The contacts are molded into a plastic holder and
cannot be easily removed. I have cleaned the metal contacts using a
diamond tip. I did this a few months ago and the contacts re-corroded.
Again cleaned but what can I do to retard corrosion? Some in place
coating or plating?


Remove the corrosion with vinegar or acid (ammonia) based window cleaner.
Put it on with a Q-Tip, let it sit and wipe it off. DO NOT spray it with
anything, including those things sold as contact cleaners.

Once the corrosion is visbaly gone, you can use a real contact cleaner,
such as Cramolin or DeOxit liquids. Again, a little bit on a Q-Tip, wipe
it off with a dry one.

There are electronic contract enhancing compounds that can be applied
sparingly to help it work. Someone else mentioned the ones used for
car batteries, but that IMHO is using a sledge hammer where a gentle tap
is needed.

More suitable to general electronics is Stabilant-22 (very expensive),
or DeOxit makes one for gold plated contacts and one for non gold contacts.

You can buy a kit containg DeOXit, cleaner, contact enhancers, and
fader lube (for lubricating variable resistors) for under $20, it will
last for many years use by the average person.

Not appropos to the original question, I have rescued many bad volume
controls with a drop of DeOxit and a drop of Fader Lube.

Whatever you do, DO NOT USE A SPRAY.

Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379

"Geoffrey S. Mendelson" wrote in message
...

Remove the corrosion with vinegar or acid (ammonia)-
based window cleaner.

Ammonia is an alkali, not an acid. I've used household ammonia for years, and
never had problems. Once the contacts were cleaned, they stayed clean.

There are disagreements among us as to whether Energizers or Duracells are
more likely to leak. Every modern battery that has leaked in my equipment has
been a Duracell. I don't use them, unless they're the only batteries
available.

On 11/22/2013 12:19 AM, Geoffrey S. Mendelson wrote:
OldGuy wrote:
Electronic flash has corroded electrical contacts. Duracell AA
batteries leaked. The contacts are molded into a plastic holder and
cannot be easily removed. I have cleaned the metal contacts using a
diamond tip. I did this a few months ago and the contacts re-corroded.
Again cleaned but what can I do to retard corrosion? Some in place
coating or plating?


Remove the corrosion with vinegar or acid (ammonia) based window cleaner.
Put it on with a Q-Tip, let it sit and wipe it off. DO NOT spray it with
anything, including those things sold as contact cleaners.

Once the corrosion is visbaly gone, you can use a real contact cleaner,
such as Cramolin or DeOxit liquids. Again, a little bit on a Q-Tip, wipe
it off with a dry one.

There are electronic contract enhancing compounds that can be applied
sparingly to help it work. Someone else mentioned the ones used for
car batteries, but that IMHO is using a sledge hammer where a gentle tap
is needed.

More suitable to general electronics is Stabilant-22 (very expensive),
or DeOxit makes one for gold plated contacts and one for non gold contacts.

You can buy a kit containg DeOXit, cleaner, contact enhancers, and
fader lube (for lubricating variable resistors) for under $20, it will
last for many years use by the average person.

Not appropos to the original question, I have rescued many bad volume
controls with a drop of DeOxit and a drop of Fader Lube.

Whatever you do, DO NOT USE A SPRAY.

Geoff.


Warning! "Fader Lube" doesn't work on all linear attenuators. It can
make some of them worse, as in stuck. Ammonia is an alkali, higher than
normal pH.

Duracell makes very crappy batteries. "The worse the product the better
the ad campaign." Sennheiser now ships with Energizer. Fry's house brand
batteries leak less than Duracells.

"Geoffrey S. Mendelson" wrote in message ...

Someone else mentioned the ones used for
car batteries, but that IMHO is using a sledge hammer where a gentle tap
is needed.

Hey! Hammers fix everything! :-)

"OldGuy" wrote in message
...
Electronic flash has corroded electrical contacts. Duracell AA batteries
leaked. The contacts are molded into a plastic holder and cannot be easily
removed. I have cleaned the metal contacts using a diamond tip. I did
this a few months ago and the contacts re-corroded. Again cleaned but what
can I do to retard corrosion? Some in place coating or plating?



--- news://freenews.netfront.net/ - complaints: ---

They have an anti-corrosion spray for car battery terminals. Clean
the terminals via what is easiest, spray some of the anti-corrosion
on some q-tips and rub on contacts.

If possible remove all pits from contacts since this tends to enhance
corrosion regardless of treatment. Filling and shaping with solder
might be an option if damage to other parts of the device will not
occur. Tricky, so this might not be an option.

What is in that spray and how does it work?
I have some that I use on car batteries.
I would think that it would insulate the cell from the contact.



--- news://freenews.netfront.net/ - complaints: ---

On Fri, 22 Nov 2013 09:45:19 -0800, OldGuy wrote:

They have an anti-corrosion spray for car battery terminals. Clean
the terminals via what is easiest, spray some of the anti-corrosion
on some q-tips and rub on contacts.

If possible remove all pits from contacts since this tends to enhance
corrosion regardless of treatment. Filling and shaping with solder
might be an option if damage to other parts of the device will not
occur. Tricky, so this might not be an option.

What is in that spray and how does it work?
I have some that I use on car batteries.

Wax or plastic coating, dissolved in various organic solvents.

For example, CRC "battery terminal protector" spray.
http://crcindustries.com/auto/?s=05046
http://www.crcindustries.com/faxdocs/msds/5046.pdf
63.5% of the contents are organic solvents and propellent:
CAS number Chemical name Common name and synonyms %
68476-86-8 Liquefied Petroleum Gas 20 - 30
64742-49-0 Naphtha (petroleum), Hydrotreated Light 20 - 30
589-34-4 3-Methylhexane 10 - 20
142-82-5 n-Heptane 10 - 20
8009-03-8 Petrolatum 10 - 20
591-76-4 2-Methylhexane 5 - 10
108-87-2 Methylcyclohexane 5 - 10
64741-88-4 Distillates (petroleum),
Solvent-refined Heavy Paraffinic 1 - 3
1330-20-7 Xylene 1 - 3
100-41-4 Ethylbenzene 1
110-54-3 n-Hexane 1
The rest is probably some form of acrylic plastic or wax, dissolved in
the above solvents, which coats the terminals. Anything that resists
water, gasoline, grease, oil, and battery acid attack, will work. Add
some red dye so it can be easily seen. The solvents are needed to
clean the terminals, remove engine grease, and help the plastic or wax
to stick to the battery terminals.

I would think that it would insulate the cell from the contact.

Nope. As long as the wax or plastic coating is sufficiently soft, the
clamping pressure of the battery clamps or screws will push the
coating out of the way and provide a good connection. If the coating
were something quite hard, it might be a different story, but not with
a soft coating. I just notice the that the CRC data sheet shows:
"Provides a lead-free soft protective coating." Note the "soft".


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Fri, 22 Nov 2013 08:19:14 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

Whatever you do, DO NOT USE A SPRAY.
Geoff.

Why? What's wrong with various cleaners in spray cans (besides the
overspray making a mess)?

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:
On Fri, 22 Nov 2013 08:19:14 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

Whatever you do, DO NOT USE A SPRAY.
Geoff.

Why? What's wrong with various cleaners in spray cans (besides the
overspray making a mess)?


They tend to damage the things you are cleaning. Many of them dissovle plastics.
Many of them casuse the wafers in wafer switches to expand and crack.

Geoff.




--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379

On Sat, 23 Nov 2013 17:04:14 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

Jeff Liebermann wrote:
On Fri, 22 Nov 2013 08:19:14 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

Whatever you do, DO NOT USE A SPRAY.
Geoff.

Why? What's wrong with various cleaners in spray cans (besides the
overspray making a mess)?

They tend to damage the things you are cleaning. Many of them dissovle plastics.
Many of them casuse the wafers in wafer switches to expand and crack.
Geoff.

OK. Do you think it's the propellent in the can that's causing the
damage? I presume everything else in the formulation is the same with
cleaners in a spray or bottle container.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Jeff Liebermann" wrote in message ...

I would think that it would insulate the cell from the contact.

Nope. As long as the wax or plastic coating is sufficiently soft, the
clamping pressure of the battery clamps or screws will push the
coating out of the way and provide a good connection. If the coating
were something quite hard, it might be a different story, but not with
a soft coating. I just notice the that the CRC data sheet shows:
"Provides a lead-free soft protective coating." Note the "soft".


Odd. Usually the cleaning is done, the termination is made, then the
protective coating is applied.

Jeff Liebermann wrote:

OK. Do you think it's the propellent in the can that's causing the
damage? I presume everything else in the formulation is the same with
cleaners in a spray or bottle container.

AFAIK it's the cleaners too. DeOxit must be carefully applied and removed.

Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379

On 11/22/2013 12:19 AM, Geoffrey S. Mendelson wrote:
OldGuy wrote:
Electronic flash has corroded electrical contacts. Duracell AA
batteries leaked. The contacts are molded into a plastic holder and
cannot be easily removed. I have cleaned the metal contacts using a
diamond tip. I did this a few months ago and the contacts re-corroded.
Again cleaned but what can I do to retard corrosion? Some in place
coating or plating?


www.flippers.com/battery.html

John :-#)#


Remove the corrosion with vinegar or acid (ammonia) based window cleaner.
Put it on with a Q-Tip, let it sit and wipe it off. DO NOT spray it with
anything, including those things sold as contact cleaners.

Once the corrosion is visbaly gone, you can use a real contact cleaner,
such as Cramolin or DeOxit liquids. Again, a little bit on a Q-Tip, wipe
it off with a dry one.

There are electronic contract enhancing compounds that can be applied
sparingly to help it work. Someone else mentioned the ones used for
car batteries, but that IMHO is using a sledge hammer where a gentle tap
is needed.

More suitable to general electronics is Stabilant-22 (very expensive),
or DeOxit makes one for gold plated contacts and one for non gold contacts.

You can buy a kit containg DeOXit, cleaner, contact enhancers, and
fader lube (for lubricating variable resistors) for under $20, it will
last for many years use by the average person.

Not appropos to the original question, I have rescued many bad volume
controls with a drop of DeOxit and a drop of Fader Lube.

Whatever you do, DO NOT USE A SPRAY.

Geoff.



--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

On Sat, 23 Nov 2013 11:44:58 -0600, Nightcrawler®
wrote:


"Jeff Liebermann" wrote in message ...

I would think that it would insulate the cell from the contact.

Nope. As long as the wax or plastic coating is sufficiently soft, the
clamping pressure of the battery clamps or screws will push the
coating out of the way and provide a good connection. If the coating
were something quite hard, it might be a different story, but not with
a soft coating. I just notice the that the CRC data sheet shows:
"Provides a lead-free soft protective coating." Note the "soft".

Odd. Usually the cleaning is done, the termination is made, then the
protective coating is applied.

Agreed and my apologies for the topic drift. The original question
was about AA batteries in an electronic flash. The question by "Old
Guy" was if an automotive battery terminal protector was suitable. My
best guess(tm) is maybe. I answered without making any distinction
between the two questions.

Apply after connection is the recommended method and the way it's
commonly done with automobile batteries. One does not want any extra
glop between the lead battery post and lead battery terminal. I have
one of those wire brush battery post/terminal cleaning tools for the
purpose.

However, I have done it the wrong way (when I was in a hurry, not
paying attention, distracted, clueless or all the aforementioned)
without ill effects. It worked because before clamping down on the
terminal locking nut, I rotated the terminal on the battery post back
and forth a few times to clean out the red stuff. It worked and no
problems.

However, the OP was asking about AA batteries in an electronic flash,
which doesn't have enough clamping pressure to clean out the wax or
plastic coating at the points of contact. Try to use automobile type
battery terminal protector on a AA spring loaded battery contact, and
there *MAY* be a problem, especially if a thick layer is applied.

I've successfully used grease and wax (furniture polish) to "protect"
battery contacts, mostly in flashlights. If I get a lousy contact, I
just spin the battery in the flashlight or holder. The flashlight
works until the grease or wax creeps into the connection again. I use
white lithium grease mostly because I have a large supply. Anything
that doesn't evaporate should work.

However, if the idea is to inhibit corrosion without coating the
terminals, I again suggest electroless tin to protect the exposed
copper.




--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Jeff Liebermann" wrote in message ...

Agreed and my apologies for the topic drift. The original question
was about AA batteries in an electronic flash. The question by "Old
Guy" was if an automotive battery terminal protector was suitable. My
best guess(tm) is maybe. I answered without making any distinction
between the two questions.

snip

No biggie, and I understand what you were stating.

On 11/23/2013 10:09 AM, Geoffrey S. Mendelson wrote:
Jeff Liebermann wrote:

OK. Do you think it's the propellent in the can that's causing the
damage? I presume everything else in the formulation is the same with
cleaners in a spray or bottle container.

AFAIK it's the cleaners too. DeOxit must be carefully applied and removed.

Geoff.


The cotton tip swab is your friend. Does anyone have any Davenol?

Ordinary spiraled spring-type replacement contacts are available from variou
suppliers. Original contacts are generally made from steel, then plated with
copper and nickel or possibly a chrome-like plating.

Many repairs require disassembly as leaking chemcas can wick into power
leads, which will often result in a chronic corrosion problem, even if the
contacts are cleaned, or the power leads might simply continue to rot.

If corroded contacts can't be thoroughly cleaned or are too far gone,
fabricating new contacts from nickel may be a worthwhile, more permanent
repair.
Nickel (round) wire is available a german silver wire for making jewelry,
and flat nickel available in strips or coils/rollls for strapping
rechargeable battery cells together to make battery packs.

Nickel easily accepts solder allowing power leads to be attached.

--
Cheers,
WB
..............


"OldGuy" wrote in message
...
Electronic flash has corroded electrical contacts. Duracell AA batteries
leaked. The contacts are molded into a plastic holder and cannot be
easily removed. I have cleaned the metal contacts using a diamond tip. I
did this a few months ago and the contacts re-corroded. Again cleaned but
what can I do to retard corrosion? Some in place coating or plating?



--- news://freenews.netfront.net/ - complaints: ---

On Thursday, November 21, 2013 7:57:17 PM UTC-8, OldGuy wrote:
Electronic flash has corroded electrical contacts. Duracell AA

batteries leaked. The contacts are molded into a plastic holder and

cannot be easily removed.

Probably the little springs are steel, with a bright nickel or
chrome plated coating (sometimes copper). If the plating has
come off, your best replacement would be...
solder.

Clean, flux (an acid flux, like for stainless steel, works best) and
then tin the spring's contact end with a soldering iron, using
tin/silver solder. Then, of course, rinse the area (to get rid of the flux).
Steel isn't a great conductor of heat, a second or two with the
soldering iron won't melt the plastic.

On Thursday, November 21, 2013 7:57:17 PM UTC-8, OldGuy wrote:

Electronic flash has corroded electrical contacts. Duracell AA
batteries leaked. The contacts are molded into a plastic holder
and cannot be easily removed.

Don't use acid -- use household ammonia, followed by an alcohol flush.

If this doesn't fix it, go to Duracell. They have a "no-leak" warranty, and
will repair or replace the unit. This happened several years ago with my
dictating machine, and Duracell made good on its warranty.

On Fri, 22 Nov 2013 05:07:11 -0800, "William Sommerwerck"
wrote:

"Geoffrey S. Mendelson" wrote in message
...

Remove the corrosion with vinegar or acid (ammonia)-
based window cleaner.

Ammonia is an alkali, not an acid. I've used household ammonia for years, and
never had problems. Once the contacts were cleaned, they stayed clean.

There are disagreements among us as to whether Energizers or Duracells are
more likely to leak. Every modern battery that has leaked in my equipment has
been a Duracell. I don't use them, unless they're the only batteries
available.

According to the chemists, ammonia is a weak acid. (So weak that some
think it is an alkali).
I recently found a duracell that leaked in something i have. Merely used
some window cleaner to remove the gunk. Shelf life OK, useful life once
installed questionable.

YMMV

?-)

"josephkk" wrote in message
...

According to the chemists, ammonia is a weak acid.

According to the Wikipedia article, "One of the most characteristic properties
of ammonia is its basicity. Ammonia is considered to be a weak base."

It also says...

"Although ammonia is well known as a weak base, it can also act as an
//extremely// weak acid. It is a protic substance and is capable of formation
of amides (which contain the NH2ˆ’ ion)."

So it appears to depend on the reaction.

Here's something else from Wikipedia. Remember litmus paper?

"The main use of litmus is to test whether a solution is acidic or basic. Wet
litmus paper can also be used to test water-soluble gases; the gas dissolves
in the water and the resulting solution colors the litmus paper. For instance,
ammonia gas, which is alkaline, colors the red litmus paper blue."

On Wed, 18 Dec 2013 03:22:34 -0800, "William Sommerwerck"
wrote:

Here's something else from Wikipedia. Remember litmus paper?

"The main use of litmus is to test whether a solution is acidic or basic. Wet
litmus paper can also be used to test water-soluble gases; the gas dissolves
in the water and the resulting solution colors the litmus paper. For instance,
ammonia gas, which is alkaline, colors the red litmus paper blue."

Well you are allowed to trot out all the low grade references you wish. Do
better fact checking and you will find out that ammonia is indeed a weak
acid. See also Lewis acid e. g. BF3 which has no hydrogen at all.

?-)

"josephkk" wrote in message
...
On Wed, 18 Dec 2013 03:22:34 -0800, "William Sommerwerck"
wrote:

Here's something else from Wikipedia. Remember litmus paper?

"The main use of litmus is to test whether a solution is acidic or basic.
Wet
litmus paper can also be used to test water-soluble gases; the gas
dissolves
in the water and the resulting solution colors the litmus paper. For
instance,
ammonia gas, which is alkaline, colors the red litmus paper blue."

Well you are allowed to trot out all the low grade references you wish. Do
better fact checking and you will find out that ammonia is indeed a weak
acid. See also Lewis acid e. g. BF3 which has no hydrogen at all.

To call Wikipedia a low-grade reference is a cheap shot. As for fact-checking,
do some yourself.

William Sommerwerck wrote:
"josephkk" wrote in message

Well you are allowed to trot out all the low grade references you wish. Do
better fact checking and you will find out that ammonia is indeed a weak
acid. See also Lewis acid e. g. BF3 which has no hydrogen at all.

To call Wikipedia a low-grade reference is a cheap shot. As for fact-checking,
do some yourself.

http://www.chem.queensu.ca/people/fa...base/index.htm
http://www.uwec.edu/lewisd/Chem321-0...-Base/Acid.htm
http://www.bbc.co.uk/bitesize/higher...ds/revision/1/
http://www.files.chem.vt.edu/chem-ed...ase/intro.html

These consistently identify ammonia (NH3) as a weak base, according to
the Bronsted-Lowry definition.

When NH3 reacts with water, the NH3 accepts a proton from the water
and generates the ammonium ion (NH4+, a weak acid), and the hydroxide
ion (OH-). The fact that NH3 accepts a proton in this reaction is
what defines it as a Bronsted-Lowry base.

According to

http://www.scienceforums.net/topic/4...mmonia-a-base/

NH3 is at least somewhat amphiprotic - in some reactions it can donate
a proton (acting as an acid) rather than accepting one.

According to

http://www.chem1.com/acad/webtext/abcon/abcon-6.html

"ammonia, is a weaker acid than H2O, so it exhibits basic properties
in water

NH3 + H2O †’ NH4+ + OH€“

but behaves as an acid in non-aqueous solvents such as liquid ammonia
itself:

NH3 + NH3 †’ NH4+ + NH2€“ "

and also says

"Ammonia is such a weak acid that its conjugate base, amide ion NH2€“,
cannot exist in water. In aqueous solution, NH3 acts as a weak base,
accepting a proton from water and leaving a OH€“ ion"

So, the answer to the question "Is ammonia a base or an acid" appears
to be "either or both, depending on the circumstances."

It's not an either/or sort of thing.

On 12/21/2013 08:34 PM, David Platt wrote:
William Sommerwerck wrote:
"josephkk" wrote in message

Well you are allowed to trot out all the low grade references you wish. Do
better fact checking and you will find out that ammonia is indeed a weak
acid. See also Lewis acid e. g. BF3 which has no hydrogen at all.

To call Wikipedia a low-grade reference is a cheap shot. As for fact-checking,
do some yourself.

http://www.chem.queensu.ca/people/fa...base/index.htm
http://www.uwec.edu/lewisd/Chem321-0...-Base/Acid.htm
http://www.bbc.co.uk/bitesize/higher...ds/revision/1/
http://www.files.chem.vt.edu/chem-ed...ase/intro.html

These consistently identify ammonia (NH3) as a weak base, according to
the Bronsted-Lowry definition.

When NH3 reacts with water, the NH3 accepts a proton from the water
and generates the ammonium ion (NH4+, a weak acid), and the hydroxide
ion (OH-). The fact that NH3 accepts a proton in this reaction is
what defines it as a Bronsted-Lowry base.

According to

http://www.scienceforums.net/topic/4...mmonia-a-base/

NH3 is at least somewhat amphiprotic - in some reactions it can donate
a proton (acting as an acid) rather than accepting one.

According to

http://www.chem1.com/acad/webtext/abcon/abcon-6.html

"ammonia, is a weaker acid than H2O, so it exhibits basic properties
in water

NH3 + H2O †’ NH4+ + OH€“

but behaves as an acid in non-aqueous solvents such as liquid ammonia
itself:

NH3 + NH3 †’ NH4+ + NH2€“ "

and also says

"Ammonia is such a weak acid that its conjugate base, amide ion NH2€“,
cannot exist in water. In aqueous solution, NH3 acts as a weak base,
accepting a proton from water and leaving a OH€“ ion"

So, the answer to the question "Is ammonia a base or an acid" appears
to be "either or both, depending on the circumstances."

It's not an either/or sort of thing.


It's great for shining brass!

"David Platt" wrote in message ...

So, the answer to the question "Is ammonia a base or an acid" appears
to be "either or both, depending on the circumstances."

Thank you for taking the time to clarify this.

"josephkk" wrote in message
...

Interesting. I am corrected, more or less. It was another
earlier odd change to shift from thinking of it a weak base
to a very weak acid. It took about the same grade of
information then as well.

And I admit to being surprised that such a simple molecule can be a proton
receptor under one set of conditions, a donor under others.

On Sat, 21 Dec 2013 20:34:56 -0800, (David Platt)
wrote:

William Sommerwerck wrote:
"josephkk" wrote in message

Well you are allowed to trot out all the low grade references you wish. Do
better fact checking and you will find out that ammonia is indeed a weak
acid. See also Lewis acid e. g. BF3 which has no hydrogen at all.

To call Wikipedia a low-grade reference is a cheap shot. As for fact-checking,
do some yourself.

http://www.chem.queensu.ca/people/fa...base/index.htm
http://www.uwec.edu/lewisd/Chem321-0...-Base/Acid.htm
http://www.bbc.co.uk/bitesize/higher...ds/revision/1/
http://www.files.chem.vt.edu/chem-ed...ase/intro.html

Interesting. I am corrected, more or less. It was another earlier odd
change to shift from thinking of it a weak base to a very weak acid. It
took about the same grade of information then as well.

These consistently identify ammonia (NH3) as a weak base, according to
the Bronsted-Lowry definition.

When NH3 reacts with water, the NH3 accepts a proton from the water
and generates the ammonium ion (NH4+, a weak acid), and the hydroxide
ion (OH-). The fact that NH3 accepts a proton in this reaction is
what defines it as a Bronsted-Lowry base.

According to

http://www.scienceforums.net/topic/4...mmonia-a-base/

NH3 is at least somewhat amphiprotic - in some reactions it can donate
a proton (acting as an acid) rather than accepting one.

According to

http://www.chem1.com/acad/webtext/abcon/abcon-6.html

"ammonia, is a weaker acid than H2O, so it exhibits basic properties
in water

NH3 + H2O †’ NH4+ + OH€“

but behaves as an acid in non-aqueous solvents such as liquid ammonia
itself:

NH3 + NH3 †’ NH4+ + NH2€“ "

and also says

"Ammonia is such a weak acid that its conjugate base, amide ion NH2€“,
cannot exist in water. In aqueous solution, NH3 acts as a weak base,
accepting a proton from water and leaving a OH€“ ion"

So, the answer to the question "Is ammonia a base or an acid" appears
to be "either or both, depending on the circumstances."

It's not an either/or sort of thing.