Tollen's Reaction

[Invader_Gir]

In this reaction, a solution of silver nitrate, potassium hydroxide, glucose, and a little ammonia are put into a flask. The flask is swirled, and the glucose reduces the silver ions and they are deposited on the wall of the flask. This reaction is a little more detailed than that, but I just wanted to give a little backround. Any ways, the question: Could sodium hydroxide be used in place of the posassium hydroxide.

 

Thanks

[akcapr]

I know KOH can be used but for some reason NaOH is prefered. Almost always NaOH is used to make this reagent. THe base is just needed to get the complex to form properly.

[Invader_Gir]

Alright thanks. But the lab manual I have calles for Potassium Hydroxide instead of Sodium.

[akcapr]

ya, just look online for tollens reagent, almost all the preperations call for NaOH.

[woelen]

It does not matter. In aqueous chemistry, nearly always you can exchange NaOH and KOH without problem. Only take into account that the same number of moles needs to be used, so for a 1 : 1 mole ratio of NaOH and KOH, you need a little more KOH than NaOH.

[insane_alien]

could it be that since Na is lighter than K the reaction procedes a little bit quicker?

[Invader_Gir]

Just a follow up question...after performing this experiment, a greyish sediment was collected via vacuum filtration. What is this compound...is there any silver in this? Would adding nitric acid make silver nitrate, so we could do the experiment again? Also, a buddy and I are making a chess table with this stuff, so the black spots are mirrored. What tape would be good to use to keep some of the squares clean. Tried a sample with painters tape, with tollerable results. Thanks again

[Invader_Gir]

I've converted most of the left over silver to AgCl. Is there anyway to then convert this to silver nitrate? Or is there way to convert silver sulfate to silver nitrate. I was thinking about trying to dissolve them in concentrated ammonia solution to make the Tollens reagent again, then reduce the ion to silver metal and just add nitric. Would this work? Or would so little dissolve that it would be futile? Thanks

[woelen]

Yes, that works quite well. You can also make silver directly out of it. Dissolve some vitamin C (e.g. from tablets) in water, filtering out the white insoluble stuff. Add NaOH to this and then add your white AgCl. This stuff becomes black very quickly. Rinse well with water in order to remove impurities. No need to dry. Simply add HNO3 to it again and you have AgNO3 again.