Silvering a Mirror or a Flask by the Tollens’ Reagent
10
Silvering a Mirror or a Flask by the Tollens’ Reagent (Demonstration by Lee Marek, PowerPoint Slides by Bob Widing)
Transcript of Silvering a Mirror or a Flask by the Tollens’ Reagent
![Page 1: Silvering a Mirror or a Flask by the Tollens’ Reagent](https://reader030.fdocuments.us/reader030/viewer/2022012602/61983a84d2f8b332fd7d26bc/html5/thumbnails/1.jpg)
Silvering a Mirror or a Flask by the Tollens’ Reagent(Demonstration by Lee Marek, PowerPoint Slides by Bob Widing)
![Page 2: Silvering a Mirror or a Flask by the Tollens’ Reagent](https://reader030.fdocuments.us/reader030/viewer/2022012602/61983a84d2f8b332fd7d26bc/html5/thumbnails/2.jpg)
Some bottles silvered by Lee Marek
![Page 3: Silvering a Mirror or a Flask by the Tollens’ Reagent](https://reader030.fdocuments.us/reader030/viewer/2022012602/61983a84d2f8b332fd7d26bc/html5/thumbnails/3.jpg)
The Tollens’ reaction oxidizes an aldehyde to a carboxylic acid salt.That oxidation drives a reduction of soluble silver ion to silver metal.
D-glucose D-gluconate,salt of gluconic acid
aldehyde
acid salt
![Page 4: Silvering a Mirror or a Flask by the Tollens’ Reagent](https://reader030.fdocuments.us/reader030/viewer/2022012602/61983a84d2f8b332fd7d26bc/html5/thumbnails/4.jpg)
Tollens’ reaction with oxidation numbers
oxidation half-reaction
reduction half-reaction
net reaction
![Page 5: Silvering a Mirror or a Flask by the Tollens’ Reagent](https://reader030.fdocuments.us/reader030/viewer/2022012602/61983a84d2f8b332fd7d26bc/html5/thumbnails/5.jpg)
Monosaccharide aldoses
![Page 6: Silvering a Mirror or a Flask by the Tollens’ Reagent](https://reader030.fdocuments.us/reader030/viewer/2022012602/61983a84d2f8b332fd7d26bc/html5/thumbnails/6.jpg)
Isomerization of ketose-to-aldosevia an enediol intermediate
(Why C2 ketoses are also reducing sugars)
![Page 7: Silvering a Mirror or a Flask by the Tollens’ Reagent](https://reader030.fdocuments.us/reader030/viewer/2022012602/61983a84d2f8b332fd7d26bc/html5/thumbnails/7.jpg)
Monosaccharide ketoses
![Page 8: Silvering a Mirror or a Flask by the Tollens’ Reagent](https://reader030.fdocuments.us/reader030/viewer/2022012602/61983a84d2f8b332fd7d26bc/html5/thumbnails/8.jpg)
Ring andChain formsof glucose
All OH are equatorial in β-D-glucose
![Page 9: Silvering a Mirror or a Flask by the Tollens’ Reagent](https://reader030.fdocuments.us/reader030/viewer/2022012602/61983a84d2f8b332fd7d26bc/html5/thumbnails/9.jpg)
Bernhard Tollens(1841-1918)
![Page 10: Silvering a Mirror or a Flask by the Tollens’ Reagent](https://reader030.fdocuments.us/reader030/viewer/2022012602/61983a84d2f8b332fd7d26bc/html5/thumbnails/10.jpg)