explosion compilation

Thanks to Conor for sending the videos in, and my Btec group for managing to get through the year without me killing one of you.

And well done to Jack for catching that bottle, very impressive.

thermit update

Different class, same experiment.

This one shows nicely why you lot were on the other side of the room.

Thanks to Arran for the video.

Still not Thermit

thermit reaction

Been doing displacement reactions involving metals with Year 9 classes this week, and there is no finer example than the reaction of aluminium with iron oxide. Also known as the Thermit reaction, the vast amount of energy released is enough to create molten iron, which in days of yore is enough to explain its use in welding railway lines together. The trouble is, it has a high activation energy and requires a magnesium fuse to get the mixture going, as seen in the video below.

aluminium + iron oxide → aluminium oxide + iron

2 Al  +  Fe₂O₃  →  Al₂O₃  +  2 Fe 

The aluminium is far more reactive than the iron and so displaces it in a violent reaction.

I like the second video here as it shows the large volume of smoke rolling over the ceiling as the reaction goes off.

 

Thanks to Jodie and Daisy for sending the videos in. 

Not the Thermit

fuels

Messing about with Year 10 for our C1 module, all about the atmosphere and fuels. A couple of good fuels here, firstly hydrogen. Very explosive, which in addition to it being a gas makes transport and storage of the fuel a challenge. However, the combustion of hydrogen results in no carbon emissions, with the only product of the reaction being water.

2 H₂  +  O₂   →  2 H₂O

Secondly methanol, a very flammable alcohol. Alcohols have the distinct advantage of being renewable fuels which can be produced from the fermentation of sugars or biomass. This means that although they will still produce carbon dioxide as they burn, they are a much more sustainable form of energy when compared to traditional fossil fuels such as coal, oil and gas.

2 CH₃OH  +  3 O₂  →  2 CO₂  +  4 H₂O

Thanks to Josh for sending both videos in.

ping pong

You may have seen the video (elsewhere on this site) of me using liquid nitrogen to make a rather crude bomb from a plastic bottle and a bin full of water. In fact, I may have even demonstrated it live for you on the all weather pitch.

However, in the video below a Plymouth University Professor has had a fine idea and has taken it one step further.

I'm now saving up for 1500 ping pong balls.

nitrogen triiodide

Strike day, and a bit of free time to play around with some home made explosives.

Nitrogen triiodide is worryingly easy to make, and extremely unstable. It is a contact explosive when dry, and produces a beautiful plume of iodine vapour mixed with nitrogen gas when detonated.



As you can see and hear from the video, the explosion is fairly impressive given the small quantity used. You can see that the metre ruler suffers for its art, and you may just be able to make out Mr Chivers' exclamation from his nearby office just as it goes off.

Anyone interested in why it's so unstable will need to consider the entropy change for the reaction.

2 NI₃ (s) → N₂ (g) + 3 I₂ (g)

The large increase in the number of moles from left to right, in addition to the production of gases from a solid, leads to an enormous increase in entropy. Also, the reaction is clearly exothermic. These two factors are ideal for giving a negative free energy change for the reaction, indicating a highly likely, spontaneous reaction.

explosion of the month 8

This month it's one of my own. This is similar to a previous post showing hydrogen burning in a pringles tub, only slightly scaled up into a large coffee tin. As the hydrogen burns from the hole in the lid, air is drawn in through the hole in the base of the tin until the mix is just right....

explosion of the month 7

According to the blurb accompanying the original video on YouTube, this blast was much larger than the navy mine clearance team intended. The black dust that appeared a few seconds after the initial explosion was the remnants of a sunk Second World War vessel caught up in the explosion, it is claimed. With that size of blast it's a wonder we didn't see any more exploding whales like last month.

explosion of the month 6

I'm a bit late with this month's explosion, but if I'd posted this earlier you would probably have thought it was an April fool's joke.

The presenter of this 1970 news clip insists that dynamite was the only way of getting rid of the dead whale that washed up on an Oregon beach. True or not, it made for an unusual blast.



For more about exploding whales (I'm serious) have a look at the link below. Apparently there was one in Taiwan that went up without even the need for dynamite.

exploding whales, honestly, who'd have thought it?

explosion of the month 5

This one is more of an eggsplosion. Ha Ha Ha.

explosion of the month 4

A fire at a rocket fuel factory. Sounds nasty.



The PEPCON disaster occurred in Henderson, Nevada on May 4, 1988 at the Pacific Engineering Production Company of Nevada (PEPCON) plant. The chemical fire and subsequent explosions claimed two lives, injured 372 people, and caused an estimated $100 million of damage.

The PEPCON plant, located just outside of Las Vegas, produced ammonium perchlorate, an oxidizer used in solid fuel rocket boosters of the type used in the Space Shuttle and military weapons.

In addition to the PEPCON plant there was also a large marshmallow factory about 500 feet away. That's a lot of toasted marsmallows.

The explosions leveled the PEPCON plant and Kidd & Co marshmallow manufacturing facility. Damage within a 1.5 mile radius was severe, including destroyed cars, damage to buildings and downed power lines. Damage to windows and moderate structure damage was recorded within three miles of the incident.

The damage reached a radius of up to 10 miles, including shattered windows, doors blown off their hinges, cracked windows and injuries from flying glass and debris. At McCarran International Airport, seven miles away in Las Vegas, windows were cracked and doors were pushed open. The shock wave even buffeted a Boeing 737 on final approach.

In short, the explosion made a bit of a mess. The irony was that with the space shuttle program frozen as a result of the 1986 Challenger disaster, there was no government instruction detailing what to do with such large quantities of product. If this had not been the case, there would probably not have been the same stockpiling of the rocket fuel on site.

explosion of the month 3

Ethyne gas, C₂H₂, (commonly called acetylene)



is often used in welding to generate the intense heat required to cut through metal. Oxyacetylene is the hottest burning common fuel gas and combustion of acetylene with oxygen produces a flame with a temperature of over 3600 K (about 3300 °C).

As you can imagine, when a cylinder of the stuff leaked in a factory in Dallas, Texas, and accidently ignited, this was not entirely good news for the nearby residents and commuters. Particularly as it was being stored with a large number of other cylinders of the gas.

explosion of the month 2

Always wear your safety goggles.
This technicolour clown got very lucky.
Judging by his reaction, I think he knows it as well.

explosion of the month 1

The 5th of November has just been and gone, but it gave me an idea for a new running feature on explosions. Let's call it Explosion of the Month.

This first one feature a man who puts anvils in orbit.



If anyone wants to find out a bit more about how he does it, follow the link below.

anvil shooting

mercury

Anyone for a pint of mercury?

This image shows a pool ball floating on liquid mercury. A pool ball is fairly heavy for its size, but you can see that it floats on, or is less dense, than the mercury. In fact, mercury is denser than lead, and metal objects like forks, coins, or even a cannonball will float on top (see video below).

Mercury, or quicksilver, can be a bit dodgy though. It can be absorbed through the skin and over time it accumulates in the system and causes heavy metal poisoning (as does, for instance, lead). Symptoms include dementia, vomiting, cramping, diarrhea and ultimately for prolonged exposure, death. One touch will not kill you, or necessarily even cause symptoms but, like all heavy metal poisoning, it accumulates in your system.

So it's probably not a good idea to sit in (or on) a bath of it. This picture was taken in 1972 and it's no wonder the poor guy can't raise a smile.

Finally, you've probably heard the term "mad as a hatter". This is thought to have originated from traditional hatmaker's use of mercury to cure the felt they used to make the hats, which caused dementia due to the prolonged exposure over the life of the milliner.

the periodic table of videos

I've put an exciting new resource into the Useful Links section down the right hand side of the blog, and also put a link from this post.

Periodic Table of Videos

It's set of short videos, one for each of the elements in the Periodic Table, produced at Nottingham University and featuring some impressive Chemistry.

Keep an eye out for the Professor with the mad grey hair.

liquid nitrogen bomb

Liqiud nitrogen boils at a temperature of −196 °C and since the liquid to gas expansion ratio is 1:694 it will very quickly build up enough pressure to make it quite unsafe to seal into an empty plastic bottle.

hydrogen pringles

A pringles tub with a small hole in the top, filled with hydrogen gas and ignited, will burn away quietly until the hydrogen/air mix is just right. Then a small explosion is observed. The second attempt has the mix just right to begin with upon ignition.

jelly baby

Basic fire triangle requirements, essential for all combustion, are heat, oxygen and fuel. Here the heat has already been provided by a bunsen, the oxygen mainly comes from the molten compound in the boiling tube, potassium chlorate, KClO₃, and the fuel? Well that's the sugar in the poor old jelly baby.

magnesium and copper oxide

The two metals magnesium and copper are poles apart in terms of reactivity, as anyone with a passing knowledge of the reactivity series of metals will be aware.

This can be violently demonstrated by the reaction between magnesium powder and copper oxide in a small porcelain crucible. It takes a while to get hot enough, and then a rather spectacular displacement reaction occurs.