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.

Update

It's been a while since I last posted here, so I thought I should give everybody an update. My YouTube page has really taken off since I started it back in March, and I already have over 130 subscribers! That being the case, I'm going to focus more on making videos than writing blog posts. I'll still put up things here, but it's hard to shoot video, take photos, and do an experiment all at the same time!

In other news, I bought my first home! Because of this, I won't be doing much science for a bit while I get settled in to my new place. The good news is that I've set aside the third bedroom for my lab space, so I'll have an entire room dedicated to my hobby. I'm very excited to get that all set up! In the meantime, stay tuned to both this blog and my YouTube page and remember to follow and subscribe to both using the links on the main pages.

Experiment: Growing Bismuth Crystals

In this experiment, I'll be growing beautiful iridescent crystals out of pure bismuth metal. These "hopper crystals," as they are known, form completely naturally as molten bismuth cools and solidifies. They aren't found in nature, however, because of the specific circumstances required to make them. People make these in labs and sell some pretty amazing samples on eBay. The process is very simple, and is easy for anyone to do at home.

Experiment: Mercury Beating Heart

This old post serves as the Video Companion to  this video.

This is an extremely cool demonstration of electrochemistry involving one of my favorite elements - mercury. It's a shame that it's so toxic, otherwise it would be incredibly fun to play with. The setup for this experiment is simple, but very difficult to get it to work in practice. A droplet of elemental mercury is placed in a solution of an electrolyte and a strong oxidizer. Next a piece of iron is brought near the drop, which then starts to oscillate and looks like a beating heart.

Get Useful Components from a Lantern Battery

Here's a cheap, easy way to get three very useful items for your own experiments - carbon, zinc, and manganese dioxide. All you need is a 6V lantern battery and a few common tools. You want to make sure you buy a carbon-zinc type battery. If it says "heavy duty" or "ultra heavy duty" on the sticker, then you're good to go. If it says alkaline anywhere on it, this procedure will not work as that uses a different battery chemistry. I used an Everready Heavy Duty battery, which didn't mention carbon-zinc, but I've seen this done before with this battery type so I knew it would work.

Experiment: Vanadium Pentoxide Thermite

Here's a quick one. This thermite was a 2.02:1 mix of V2O5:Al powder. Vanadium pentoxide is a (fairly toxic) orange powder, and it made a sandy colored thermite mix. It reacts via the equation

10Al + 3V2O5 -> 5Al2O3 + 6V

I was only able to get one good picture of the actual reaction because it happens so fast - its more like a small explosion! It produced some very bright white sparks, a color that the camera didn't capture too well. I thought it was going to start a brush fire afterward, as you can see in the last two photos by all the fire! I was able to find some small pieces of vanadium in the aftermath - a lot of which was lying in the sand nearby. Some pieces had some tarnish on them, giving them a neat iridescent purpleish shine.

Experiment: Tin Oxide Thermite

Another thermite composition - 4.19:1 SnO2:Al by weight, with about 25g total thermite. I already had tin samples for my collection, but every thermite produces a different reaction so I wanted to try it out. I wasn't disappointed. This one produced a lot of smoke and some bright sparks, following the reaction
4Al + 3SnO2 -> 2Al2O3 + 3Sn
I recovered a lump of tin caked in alumina slag that I could not easily remove since tin is so soft. I melted the piece in a crucible and was able to pour off some (relatively) pure tin that was nice and shiny. As you can see in the last picture I recovered almost 4g of tin, which was about a 20% yield.

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).

Experiment: Silicon Dioxide Thermite

This old post serves as the Video Companion to  this video. This reaction was done some time before the video was shot, so some conditions here were a bit different (e.g. the ignition method).

This one was one of my favorite experiments to date. The silicon dioxide I used was common beach sand. I picked it up off the ground from Panama City Beach, ground it down to a finer powder in a mortar and pestile, and mixed it into thermite. This composition is extremely hard to ignite, so I added sulfur as well. This sets up a helper reaction between sulfur and aluminum that burns hot enough to sustain the rest of the thermite. The ratio I used was 9:12:10 SiO2:S:Al. This experiment was done when I was trying out different ignition methods, so here I used "thermite ignition mixture" from www.unitednuclear.com (my favorite science supplier), which was ignited with an M-80 fuse.

Experiment: Black Iron Oxide Thermite

Thermite is most commonly made with red iron oxide (hematite, or common rust), but I went with black iron oxide (magnetite) because it should yield more metal per reaction. The ratio for this is 3.22:1 Fe3O4:Al by weight.

Full reaction: 8Al + 3Fe3O4 -> 9Fe + 4Al2O3

Experiment: Manganese Dioxide Thermite

This old post serves as the Video Companion to  this video.

For this experiment, I used manganese dioxide and a much finer aluminum powder than in my other thermites, at a ratio of 2.42:1 MnO2:Al by weight (40g total). I've done this reaction before (but forgot to photograph it), and using my normal aluminum it produced a reaction similar to the iron thermite. It was a little brighter and produced more sparks. With the finer powder, things went a little differently. The small flower pot erupted in a pillar of flame about 6 feet high, with the sound of a rocket engine and heat that was felt a good 15 feet away. This is a great demonstration of the importance of particle size in thermite and most other reactions. I plan on posting a direct comparison, complete with pictures, sometime in the future.

Background: Thermite

One of the first experiments I did at my home lab, and the type I've done most often, is the thermite reaction. This is the exothermic reaction between a powdered metal oxide and a pure metal, most commonly between iron oxide and aluminum. The strength of the reaction can be determined by how far apart the two metals are in the Activity Series. For example, a copper oxide thermite should be more violent than a chromium oxide one since copper is farther from aluminum on the series than chromium (and it is, by a lot). Thermite involves a single-replacement reaction, where the more reactive aluminum replaces the other metal in its oxide, resulting in alumina (aluminum oxide) and the pure metal. The reaction is hot enough to occur in the liquid stage, so the products are generally in one solid lump after cooling. Thermite is used in some welding applications, and was used in special grenades in the military.

The Home Scientist: About

Welcome to The Home Scientist!

I created this blog to document and share my scientific experiments with anyone that cares to read about them. This all started with my decision to start an element collection. I'm collecting samples of every element from the periodic table that is obtainable. That leaves me with 92 elements, from Hydrogen to Uranium. Some are common around the house, some can be bought online, and others can be obtained through chemical reactions. The last is what prompted me to build my home laboratory, and the desire to document my experiments lead me to make this blog. It might have been boring in school, but I bet your chemistry class never did stuff this cool.

Also, I hope that by sharing my experiences I can get people interested in science. Sometimes the school system presents the material as too mathematical or not as fun as it can be, and kids lose interest. The fun of all science, and chemistry in particular, is in my opinion all in the experiments. Science is all about curiosity and the drive to know just how the world works, and getting kids interested early on will, if nothing else, help to open their eyes to see the wonders of the universe we live in.

With all that said, I have to put a disclaimer for anything you see on this site. Everything I do at my home, you probably shouldn't do at yours. I have years of education in laboratory safety and practices, and have worked with chemicals in three different research labs. While I'm not discouraging other people's own scientific pursuits, I have to emphasize that you exercise extreme caution and wear proper safety gear if you ever do anything like what I do.

So enjoy reading, please comment and become a follower, and again welcome to The Home Scientist!