Electrolysis seems to be one of the topics that comes up top during my online Chemistry tutoring sessions. So I am starting a short series of blog posts just on this topic aimed at GCSE students. Firstly, we must ask what the meaning of Electrolysis is:
- Electro – broadly speaking to do with electricity and the flow of electrons.
- lysis – breaking down, decomposing, loosening etc.
What we did there was to break up the word into its components. Well, that is not too far from the very process of electrolysis itself! Thanks to electricity we were able to discover elements that we previously had no idea that existed. The periodic table grew pretty fast due to this.
So thinking in terms of simple metal -non metal compounds, electrolysis simply reverses the process of ionic bonding and breaks the compound into the original elements it was formed from. This is only possible through a flow of electrons in a circuit, which is provided by the cell.
Seeing is believing so here is a short video that shows solid lead bromide melted under some intense heat and then given the electrolysis treatment.
The reactivity of the metals determines how abundantly they are found on the earth. And an appreciation of their reactivity gives us a timeline of our own development as a species. A study of the reactivity of metals is also a study of very own history. This part of AQA and Edexcel GCSE is one I go through with students all the time. How the Bronze age started and then the Iron Age. All linked to the reactivity series.
Early Bronze Age Tools
Pre-historic humans used stone tools and items in their day to day lives. Tool making was a big deal indeed. But we couldn’t have known of metals besides silver and gold as they were all locked away in unrecognisable oxide form.
A most remarkable discovery moved us from the Stone Age period into the Bronze age. Bronze is an alloy (mixture of metals) of Copper and Tin. And copper would have been found as copper ore in nature. An accidental hot fire near a copper ore in the presence of coal (which contains Carbon, which is more reactive than Copper) would have revealed copper’s true existence. The Carbon reduced the Copper Oxide into Copper. A beautiful gold like substance, soft and malleable. It must have been an extraordinary discovery of its time and it changed the game for humans. We were now able to make much much more sophisticated tooling, ornaments and jewelry. It was the first metal we discovered and set us on a path to more discoveries later.
Here are a couple of great videos that show how a green ore of Copper called Malachite can easily be reduced into Copper. The implications of discovering Copper, and how it was a prime trade item are shown on the videos.
This is a superb resource for GCSE AQA Chemistry students studying the C2 module, or the iGCSE Edexcel 1C modules, both of which I tutor. And if as a student you are feeling bogged down by learning cold facts, then these videos will bring it all to life again.
Do you have any thoughts on the magic of Copper? Feel free to comment 🙂
A couple of Welsh children, the animated curious cat, Fur Elise by Beethoven, blast furnaces, biscuit tins, 3rd year undergraduates, iron ore and GCSE Chemistry. What’s all this about? And how can this help with your Chemistry revision?
Blast Furnace and Iron Extraction
There are some superb educational videos out there that I use for my tutoring resources when tutoring Science online, and this one linked below is one of my absolute favourites!
The extraction of iron from iron ore in a blast furnace followed by its conversion into steel is a well known process in the industrial world. And what better way to appreciate this than to see for real how this process happens? This video comes in very handy to me when I am tutoring GCSE Chemistry online. In particular the C1 and C2 modules for AQA Science. Also for the iGCSE Edexcel Chemistry syllabus.
But this video, which is made for primary school children is very versatile indeed. I first used this with a Materials Engineering undergraduate in his third year when we were doing rolling mill calculations for hot steel slabs. The calculations were very complex and at times I felt that we were losing track of what the point of the calculations were. So as always I found a video of the whole steel plate manufacturing process, starting from iron ore, going to the blast iron furnace, then going to the blast oxygen furnace, hot rolling of slabs, cold rolling of slabs, to eventually making the tins.
A couple of Welsh children ask the curios cat in this video on how biscuit tins are made. They are transported to a journey where they steel plants and tin factories. So click on the link above and get transported yourself. The music is very good too, especially at the end with Beethoven’s Fur Elise.
Anyone who knows me knows that two things that I really love are tutoring (with any practical element in it) and rock music. It is awesome that the two have been so flawlessly combined in this video.
Chemistry is really best experienced by doing experiments yourself. But that’s not always possible and thanks to the world of sharing videos, we now have the next best thing. To see videos of experiments. This is a lot better than reading about it. In this video a school Science teacher demonstrates the three core gas test that are relevant for GCSE and Common Entrance 13+ Chemistry. Here they are as shown on the video
- Oxygen – Will re-light a glowing splint.
- Hydrogen – A squeaky pop sound is heard as the Hydrogen is lit.
- Carbon dioxide – As Carbon dioxide gas is passed through clear limewater, it goes cloudy/milky coloured. Carbon dioxide will also put out a flame. This is why it is used in some fire extinguishers
So there you have it, a very clear and Joe Satriani type rock ‘n roll guitar soundtrack to demonstrate some of the most basic Chemistry gas tests. The tune is called “The Redshift Riders”. Satch must know his Physics as well to use that name 🙂