[Tricka90]

According to my chemistry handbook, silver nitrate is made by dissolving pure silver in concentrated nitric acid and then let the solution rest in a dark place for a few days until silver nitrate crystals precipitate. I'm wondering if I can save time by just boiling the solution instead, until all nitric acid is evaporated and I'm left with only the solid precipitate of silver nitrate. Do you think it is a good idea? It doesn't seem silver nitrate is affected by heat (though it is photosensitive) so if I vigorously boil and stir the solution for one hour or so I'll be able to obtain the crystals faster, I'm I right?

[AWK]

See wikipedia: silver nitrate (solubility!)
It is stable to light in the presence of some nitric acid in solution.

[Tricka90]

See wikipedia: silver nitrate (solubility!)
It is stable to light in the presence of some nitric acid in solution.

I'm sorry I don't understand, does it mean I can boil it or not?

[AWK]

If you have solubility at 100 C  given, you can boil solution. But at boiling temperature of concentrated solution ~120 C the solubility of silver nitrate is over 1kg/100g of water. Hence you can easily overheat dry salt with its decomposition. To prevent photochemical decomposition add a drop (just one drop) of diluted (just one drop) nitric acid to concentrated solution. And for goodness sake leave solution for crystallization in darkness.

[Arkcon]

Do look up some of the properties of boiling nitric acid.  Heck, spend some time considering -- how do I boil, plain water, in the dark, with complete safety?  Its up to each Citizen Chemist to determine what engineering protocols for lab safety are required.  That includes just not doing some pointlessly risky things.

[Tricka90]

If you have solubility at 100 C  given, you can boil solution. But at boiling temperature of concentrated solution ~120 C the solubility of silver nitrate is over 1kg/100g of water. Hence you can easily overheat dry salt with its decomposition. To prevent photochemical decomposition add a drop (just one drop) of diluted (just one drop) nitric acid to concentrated solution. And for goodness sake leave solution for crystallization in darkness.

Thank you. So if I boil too much the solution I would start losing some silver nitrate because it would start decomposing in silver, nitric dioxide and oxigen, is that correct? So that's why my handbook suggest to just leave it in a dark place for a few days, so that I will not loose any, right?

[AWK]

Calculate an approximate amount of silver salt then evaporate solution to volume = mass of salt (number) ie 10 g salt = final volume ~10 ml. This solution leave in darkness for slow crystallization.
Remember about 1 drop od diluted nitric acid.

[Tricka90]

Calculate an approximate amount of silver salt then evaporate solution to volume = mass of salt (number) ie 10 g salt = final volume ~10 ml. This solution leave in darkness for slow crystallization.
Remember about 1 drop od diluted nitric acid.

Thank you, now it's clear what I have to do, that's good.
I'm definitely going to do it that way.
If I make a mistake and boil too much I will start to see a brown gas (nitric dioxide) and some grey powder on the bottom of the flask (elemental silver) due to the decomposition of silver nitrate, is that right? I hope it won't happen but if it does I will immediately stop providing heat to the solution.

[AWK]

According to my suggestion crystallization start at ~20 C. Decomposition of silver nitrate may give Ag₂O or Ag (higher temperature). Dilute nitric acid dissolve both.

[jasongnome]

You seriously need to think of the safety aspects of this. I have a proper lab with a legal fume hood, and I wouldn't boil concentrated nitric acid here.