Chemistry – Fuel Fail
Topic: Common alkenes, their uses and chemical formulas
Professor: Yeah, nearly finished, a perpetual motion machine. This thing is going to revolutionise the world. But it still needs a little octane to get it started. Steve, can you go down to the store room and get me one litre of octane? Thanks
Steve: sure thing. Octane. No problem. Octane
Professor: Oh, hey, did you know that octane is a member of the alkane family of petrochemicals? Do you know where alkanes, alkenes, and alkyenes come from and the differences between them? If you don’t, try and find out. Anyway, they all come from crude oil and natural gas and most machines or engines need some form of petrochemicals to work.
So where do the petrochemicals that are used in the Czech Republic come from? If you don´t know that try and find it out as well.
Steve: octane? Which one is octane? None of these containers have names on them. Just a chemical formula. Look at this one there are 3 carbon atoms and 8 hydrogen atoms in the picture, does that mean it's octane or something else?
(to camera) do you know? What is C
3
H
8
? Puuuufff.
Professor: hmm, Steve is looking in the wrong place, C
3
H
8 is not octane, it’s propane. Do you know anything about propane? It is naturally a gas, b ut it’s often compressed to be a liquid so it can be easily transported. Propane is commonly used as a fuel in camping stoves or cookers, barbecues, or central heating systems for the home.
Propane is often mixed with butane, C
4
H
10
, which makes a vehicle fuel known as liquefied petroleum gas or LPG.
Steve: C
3
H
8
is Propane; I knew that, I was just testing you.
Hm ah, so this tank here has the chemical formula CH
4
. What is CH
4
? Do you know what it is?

Professor: Noo, I hope Steve doesn’t bring me some CH
4
. CH
4
is Methane. Methane is the main component of natural gas and it´s highly explosive when mixed with air. There is a lot of
Methane in the world so it is not an attractive fuel b ut it´s not what I need.
Steve: Methane is CH
4
, I know that cows make a lot of methane and that it is a relatively strong greenhouse gas, and that’s not the octane he asked for. Hmmm but this one C
8
H
18
, do you think I have finally found Octane?
Professor: Great, Steve has finally found the octane I need. Octane is highly flammable and used in petrol for cars. I just hope it works in my new perpetual motion machine.
Steve: Auh, one litre of octane, perfect! (Steve is back upstairs) Here you are. A litre of octane just as you asked for. So what is a perpetual motion machine?
Professor: A perpetual motion machine is a machine that can keep running for ever, and it uses no more energy than it creates. It could supply all the world’s energy needs and solve all the environmental problems related to energy production.
Steve: and you have invented one! But I thought that was impossible because of the laws of thermodynamics... or or something.
Professor: Well let’s start it up and see, put in the octane and away it goes! Ha ha, it works, it wo rks, it really works, my perpetual motion machine works. I’m a genius! The Nobel Prize for me!
(We see professor sleeping in his chair in the lab)
Steve: Wake up, wake up. Come on we’ve work to do!

Professor: Oh man, I was asleep, I should wake up.
Steve: Hey, you were talking in your sleep you know? You kept saying perpetual motion machine. What is a perpetual motion machine?
Professor: Oh... Just a dream Steve, just a dream... Hey, I may have been dreaming but don´t forget to find out about different petrochemicals. Good luck, (yawn) ciao for now.