Golden Rain

This post is the video companion to this video.

This experiment is hands-down the most beautiful chemistry demonstration I've ever seen. I'll be synthesizing lead(II) iodide, which has a beautiful golden yellow color. This experiment is especially striking because this bright yellow solid is produced from two water-clear solutions.

Materials

• 1.0 g Potassium Iodide, KI
• 0.8 g Lead Nitrate, Pb(NO₃)₂
• 500 mL Distilled Water

Reaction

Pb(NO₃)₂ (aq) + 2KI (aq) --> 2KNO₃ (aq) + PbI₂ (s)

Chevreul's Salt

This post is the Video Companion to this video.

Chevreul's Salt is a little-known copper compound that is quite easy to prepare, and has a few very interesting properties. In this post, I'll go over in detail what I did.

This experiment only requires two materials: copper sulfate and sodium metabisulfite. The former is sold at hardware stores as root killer for plumbing, and the latter is commonly found on eBay (since it is used by gold recovery people).

Potassium Chlorate from Bleach

This post serves as the Video Companion to this video.

This experiment was also featured on Hack a Day!

In this simple experiment you can create potassium chlorate, a powerful oxidizer that finds use in amateur rocketry, a convenient source of oxygen, and the famous "screaming gummy bear" demo (among other things), from common household items with a minimum of effort. The tradeoff is that it's a very inefficient process and yields tend to be very low. Electrolysis is a far superior method, and is something I plan on trying out in the future.

Copper Compound Conundrum, Part 3

Copper Compound Conundrum Part 3: Testing the Precipitate - the exciting conclusion!

Now that I had determined the identity of the solution, it was time to figure out what the blue precipitate was. Remember from Part 2, this is what my mystery concoction looked like (in the beaker on the right).

Copper Compound Conundrum, Part 2

Copper Compound Conundrum Part 2: Testing the Solution

If you remember from my last post, my reaction scheme for this was the following:

1) CuSO4 + 2NaHCO3 == CuCO3 + Na2SO4 + CO2 + H2O
2) CuCO3 + 2HCl == CuCl2 + CO2 + H2O
3) CuCl2 + 2NaOH == Cu(OH)2 + 2NaCl
4) Cu(OH)2 + H2SO4 == CuSO4 + 2H2O

After performing step 3 and filtering and drying the precipitate, I ended up with a dark green powder which was likely a mix of copper(II) hydroxide, oxide, and carbonate. All three of these compounds should react with sulfuric acid to form copper sulfate, so I figured I'd go ahead with the last step in my video's reaction scheme anyway. I should have ended up dissolving all the solids into a nice blue solution of copper sulfate like I started with. Here's what actually happened.

Copper Compound Conundrum, Part 1

If you've been following my blog, you've probably realized I like to write a lot. Well this one's no exception. I like to provide as much detail as possible so others can replicate my results and in reading it get the same enjoyment out of the experience as I did (hopefully). Enjoy!


In the process of filming a new video on copper compounds for my channel, I ran across a bit of a snag that ended up taking me down a different path that was both fun and instructive.

The Long Road to Copper (I) Iodide

It's been a while since my last post, because I've focused more on my YouTube account (linked on the main page). However, recently I did a rather long chain of experiments that I haven't taken video of, and so I thought would work better as a blog post with a few photos. This post, as the title suggests, is long. You were warned.

Experiment: Silver Tree

This old post serves as a video companion to this video on my YouTube channel.

This is an experiment I've had since the very beginning of my home laboratory, but for some reason I never got around to doing it. This is a single replacement reaction that precipitates pure silver metal out of a solution of silver nitrate in the presence of solid copper metal. The silver grows on the copper in very fine, hairlike crystals. After a while, they become thick enough to look almost like clouds (see the photos below). The reaction goes fairly quickly at first then slows down - mine appeared to be done after about 30 minutes, but I left it to stew for a few hours to make sure I got all the silver out of solution.

Experiment: Chemical Color Changer

A video of this reaction can be seen here.

This experiment is a simple way of making a solution that changes color on its own through purple, blue, green, and yellow. I decided to try something different for this one - it doesn't end in fire! It's still pretty interesting though, and actually very easy to do with relatively common ingredients. All you need is water, sugar, sodium hydroxide (NaOH, also called lye, a cleaner), and potassium permanganate (KMnO4, a disinfectant and water treatment chemical).