Chemistry 1010
Explosives
Black Powder
Early explosives were made from mixing pure elements and salts into a combustible powder.
15 % wood charcoal
10 % sulfur75 % salt peter (KNO3 – From Bird Droppings)
Black Powder
Chemical Reaction
10 KNO3 + 11 C + 4 S 5 CO + 5 CO2 + 5 N2 + K2CO3 + 3 K2SO4 + K2S gases
From yahoo images
smoke
Why Do Things Explode
• Demo – Vinegar and Baking Soda
From yahoo images
Firecracker
Why does it make the noise?
From yahoo images
So How Does A Bullet Work?
From yahoo images
High Explosives
• The discovery of Gun Cotton
From yahoo images
High ExplosivesDiscovery of nitroglycerine• 1867 Alfred Nobel patented
nitroglycerine• too unstable for real use in blasting
and warfare• When mixed with charcoal or silicon it
is stable• This is called dynamite• These discoveries brought Nobel a lot
of money• In his will, he left money to start the
Nobel Prize• This is still awarded annually to great
scientists
What Makes an Explosive
• Molecule with highly strained bonds
• A molecule with weakly bonded atoms
• Bonds should give off lots of energy when broken
• A molecule that when reacted produces products with very strong bonds
Energy released is the difference in energy given off when a bond breaks and the energy
absorbed when a bond forms
Weak Bond
High Explosives
• Trinitrophenols – explosive due to the easily broken N-O bond
picric acid
Picric acid was a very unstable explosive which would explode unexpectedly
Trinitrotoluene (TNT)
TNT is more stable and need detonation to explode – better bombs
C4 Explosive
See How stuff works dot com– http://science.howstuffworks.com/c-41.htm
See youtube
http://www.youtube.com/watch?v=sdBQtfRS6mI