Re: Silver Nitrate solubility
John L. Bordley, Jr. (jbordley@seraph1.sewanee.edu)
Tue, 30 Aug 94 12:16:07 CDT
>>
>>
>> >A question for anyone who can answer it. I made a 10% silver nitrate
>> >solution, but the silver doesn't seem to have fully disolved. Is it
>> >supposed to? Or do I just shake it up before I use it (I doubt it.)
>> >I haven't read a single thing about making the silver solution, so
>> >it must be extremely simple. But I'm still confused.
>> >
>> >Thanks,
>> >Adam
>>
>> The Handbook of Chemistry and Physics has a table of the solubility of
>> silver nitrate. According to it, you could have up to a 40% solution! 10%
>> by weight would be 10 g of silver nitrate per 100 g of water (or,
>> essentially, 100 ml of water). Thorough mixing may be necessary - rocking
>> (inverting) the closed container several times should help. Maybe there is
>> some impurity in your solid silver nitrate. If that is the case you might
>> want to let the solid settle and decant the liquid into another container.
>> Use a brown bottle, of course, because of the light sensitivity.
>>
>> John Bordley
>>
>>
>>
> This is my first posting to ANY list, so please please bear
>with me if I err in any way.
>
> I am guessing here, but if Adam used tap water instead of
>distilled water, any chlorides in the tap water will result in
>a milky silver nitrate solution, due to the formation of silver
>chloride. My source (Robinson and Abney, "The Art and Practice
>of Silver Printing", 1881) recommends that if this is the case,
>it must be filtered out, although I do not know what that means.
>
> Now a question I have about a silver nitrate solution is
>that the stuff I have read recommends that the solution be heated
>(about 100 degrees F) before use. Any comments on the necessity
>of this?
>
> Chico Seay
Very good idea about the possible silver chloride precipitate. Most tap
water certainly contains chloride ions and would cause the precipitate -
should be white. Deionized or distilled water should be free of chloride
ions. Filtering means to pour the solution through a piece of (usually)
filter paper in a funnel - the precipitate should be collected in the
filter paper; the clear solution of silver nitrate should pass through the
filter paper into a collecting vessel below. OR, you could wait for the
silver chloride to settle down and then decant (pour off the upper, liquid
layer) the solution.
Interesting about the 100 deg F. In general, heating a solution will
hasten the dissolving process. One must always be careful that the heating
doesn't cause some reaction to take place! 100 deg F for this solution
should be no problem.
John Bordley