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I am attempting to carry out the tollens reagent test to re-create a mirror finish, however the solution stays clear and never changes, even over a 20 minute period of heating and swirling, i have attempted the same test twice using same method to ensure not a mistake, but it just wont work.
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Mixtures are:
Silver nitrate.0.1 molar (approx)... 3.4g 95%-100% particulate to 200ml De-ionised water
Sodium hydroxide 0.4 molar (approx)... 3.2g particulate to 200ml ""
Ammonia 1.0 molar (approx)... 11ml of 33% stock solution to 200ml ""
1g household sugar
I am mixing in a testube that is only rinsed with De-ionised water nitric acid seems the standard on the examples ive seen but dont have any so assuming not important for the test but only for increased clarity of the mirroring effect.
Step 1. 10ml of silver nitrate 0.1m
Step 2. Add drops of sodium hydroxide 0.4m to form precipitate of silver oxide?
Step 3. Add drops of ammonia 1.0m till clear
Step 4. Add 1g household sugar
Step 5. Heat using paint stripper heat gun < 600 degrees Celsius.
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Is it because i am using household sugar instead of pure glucose?
Can you see an error in my method or mixing measures?
I have seen that using a sensitiser such as tin(II)chloride stabilised in hydrochloric acid can help speed up the process, which is my next step after first carrying out the test successfully.
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how can mirrors be real if our eyes arent real
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lmao you think /sci/ is actually about science
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>>8563978
I'm not a chemist or anything, but I think using Sucrose instead of Glucose could be an issue. They're not the same.
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>>8563978
This is OP
/thread
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>>8564008
at least someone has read the thread
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>>8563978
Will return to inspect this, OP. However, what sources are you using to guide you through the procedure? Just wikipedia?
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>>8564065
backyard scientist
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>>8564065
Youtube vids and instructables... Pretty sure its the sucrose vs glucose argument that is affecting things
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>>8564131
It is. Glucose is a reducing sugar whereas sucrose is not.
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>>8564075
>>8564131
Well, a quick google search reveals that sucrose is a non-reducing sugar. Glucose, however, *is* a reducing sugar. So just use glucose and you should be set.
Why do you need a reducing sugar, you might ask?
Well, in your reaction you go as far as making silver oxide. However, if you google what silver oxide looks like, it's merely a black-ish/purple-ish powder. You want the mirror-like shine of elemental silver. The only way to make your silver oxide ditch the oxygen (and in doing so, become pure silver) is to give electrons to the silver atom in the silver oxide complex.
Through some chemistry wizardry that I don't know because sugar compounds stay within the realm of biochem as far as I'm concerned, your glucose can donate those electrons to the silver oxide and give you the elemental silver you desire.
Links below explain why sucrose isn't a reducing sugar (and therefore why sucrose won't work in this experiment).
Hopefully a more chemistry-experienced anon can correct me if I'm wrong, as I'm a bit rusty.
tl;dr only use reducing sugars (one of which is glucose, there are likely some others)
Links I used:
https://www.reference.com/science/sucrose-reducing-sugar-1dd1b686f30d3190
http://www.bioinfo.org.cn/book/biochemistry/chapt11/bio1.htm
Links you should check out:
http://www.chymist.com/silver%20flask.pdf
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>>8564008
You could just as easily use high fructose corn syrup as well because fructose is also a reducing sugar.
Side note, can you use reducing sugars in place of proper reducing agents?
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I really want to do this now, because I've been trying to find an excuse to buy some silver nitrate and those bottles in the OP look tight af. What would be a good, commonly available source of glucose? Would just regular old corn syrup work?
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>>8565092
corn syrup is a mix of sugars
you can just buy bulk glucose/dextrose on amazon
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