The oxidation of reducing sugars by silver ions to form a silver mirror is a classic chemistry experiment. In this experiment, sugars that contain aldehyde functional groups are reacted with an ammonia-silver complex to form silver metal, which forms a shiny metallic mirror:

3 Ag(NH₃)²⁺(aq) + C₆H₁₂O₆(aq) + 3 OH^-(aq) → 3 Ag(s) + C₆H₁₁O₇(aq) +  6 NH₃(aq) + 2 H₂O

The simple sugars glucose, fructose, and galactose all contain aldehyde functional groups, and therefore can participate in this reaction. Such sugars are called reducing sugars. Regular table sugar (sucrose) contains a ketone functional group rather than an aldehyde group. Therefore, regular table sugar cannot be used in this experiment.

Because Powerade is sweetened with high fructose corn syrup, which consists of a lot of fructose and glucose, I wondered if PowerAde could be used as a source of reducing sugars in this experiment. You can see the results of my investigation below:

Video 1: Making a Silver Mirror using Powerade on Tommy Technicium YouTube Channel, April 28, 2020

I was concerned that using PowerAde wouldn’t work. That’s because the recipe I usually use for this experiment calls for a 0.5 M glucose solution as the source of reducing sugar. According to its nutritional label, Powerade has 21 grams of sugar in a 360 mL serving. If all the sugar in Powerade is either glucose or fructose (both of which have a molar mass of 180 g mol-1), then the concentration of reducing sugars in PowerAde is roughly 0.32 M – a bit more dilute than my normal recipe. I did notice it took a little longer for the silver mirror to plate than I am used to, which shouldn’t surprise me on account of the lower reducing sugar concentration.

I thought it would be fun to use this experiment to celebrate Christmas this year. You see, my mom and two of my aunts used to sing “Silver Bells” at my grandma’s house every Christmas day. Inspired by this memory, I decided to use this experiment to make my mom a silvery, bell-shaped flask:

Video 2: Silver Bells: A Chemistry Experiment for Christmas, Tommy Technicium YouTube Channel, December 23, 2020

Happy Holidays, everyone…and happy experimenting!

Reference

1. Shakhashiri, B.Z., Chemical Demonstrations: A Handbook for Teachers of Chemistry, volume 4, pp. 240-243.