25-08-2017, 09:32 PM
EXPLOSIVES:
[attachment=42269]
Effects of an Explosion: Blast Pressure
At the time of detonation, the gases can rush out at velocities of up to 7,000 mph and can exert pressure of up to 700 tons per square inch.
This gas travels in a outward circular pattern like a giant wave, smashing and shattering everything in its path.
Balancing Chemical Explosion Equations
* The progression is from top to bottom; you may skip steps that are not applicable, but you never back up.
* At each separate step there are never more than two compositions and two products.
* At the conclusion of the balancing, elemental forms, nitrogen, oxygen, and hydrogen, are always found in diatomic form.
Example, TNT: C6H2(NO2)3CH3; constituents: 7C + 5H + 3N + 6O
Using the order of priorities priority 4 gives the first reaction products:
7C + 6O -> 6CO with one mol of carbon remaining
Next, since all the oxygen has been combined with the carbon to form CO, priority 7 results in:
3N -> 1.5N2
Finally, priority 9 results in: 5H > 2.5H2
The balanced equation, showing the products of reaction resulting from the detonation of TNT is:
C6H2(NO2)3CH3 -> 6CO + 2.5H2 + 1.5N2 + C
The number of moles of gas formed is 10. The product, carbon, is a solid.
Volume of Products of Explosion
The molecular volume of any gas at 0 °C and under normal atmospheric pressure is very nearly 22.4 liters or 22.4 cubic decimeters. Thus, considering the nitroglycerin reaction.
C3H5(NO3)3 -> 3CO2 + 2.5H2O + 1.5N2 + .25O2
One mole of nitroglycerin produces 3 + 2.5 + 1.5 + .25 = 7.25 molecular volumes of gas; and these molecular volumes at 0 °C and atmospheric pressure form an actual volume of 7.25 X 22.4 = 162.4 liters of gas. (Note that the products H2O and CO2 are in their gaseous form.)
Further, by employing Charles' Law for perfect gases, the volume of the products of explosion may also be calculated for any given temperature. This law states that at a constant pressure a perfect gas expands 1/273 of its volume at 0 °C, for each degree of rise in temperature.
Therefore, at 15 °C the molecular volume of any gas is,
V15 = 22.4 (1 + 15/273) = 23.63 liters per mol
Thus, at 15 °C the volume of gas produced by the explosive decomposition of one gram molecule of nitroglycerin becomes
V = 23.63 l (7.25 mol) = 171.3 liters/mo
[attachment=42269]
Effects of an Explosion: Blast Pressure
At the time of detonation, the gases can rush out at velocities of up to 7,000 mph and can exert pressure of up to 700 tons per square inch.
This gas travels in a outward circular pattern like a giant wave, smashing and shattering everything in its path.
Balancing Chemical Explosion Equations
* The progression is from top to bottom; you may skip steps that are not applicable, but you never back up.
* At each separate step there are never more than two compositions and two products.
* At the conclusion of the balancing, elemental forms, nitrogen, oxygen, and hydrogen, are always found in diatomic form.
Example, TNT: C6H2(NO2)3CH3; constituents: 7C + 5H + 3N + 6O
Using the order of priorities priority 4 gives the first reaction products:
7C + 6O -> 6CO with one mol of carbon remaining
Next, since all the oxygen has been combined with the carbon to form CO, priority 7 results in:
3N -> 1.5N2
Finally, priority 9 results in: 5H > 2.5H2
The balanced equation, showing the products of reaction resulting from the detonation of TNT is:
C6H2(NO2)3CH3 -> 6CO + 2.5H2 + 1.5N2 + C
The number of moles of gas formed is 10. The product, carbon, is a solid.
Volume of Products of Explosion
The molecular volume of any gas at 0 °C and under normal atmospheric pressure is very nearly 22.4 liters or 22.4 cubic decimeters. Thus, considering the nitroglycerin reaction.
C3H5(NO3)3 -> 3CO2 + 2.5H2O + 1.5N2 + .25O2
One mole of nitroglycerin produces 3 + 2.5 + 1.5 + .25 = 7.25 molecular volumes of gas; and these molecular volumes at 0 °C and atmospheric pressure form an actual volume of 7.25 X 22.4 = 162.4 liters of gas. (Note that the products H2O and CO2 are in their gaseous form.)
Further, by employing Charles' Law for perfect gases, the volume of the products of explosion may also be calculated for any given temperature. This law states that at a constant pressure a perfect gas expands 1/273 of its volume at 0 °C, for each degree of rise in temperature.
Therefore, at 15 °C the molecular volume of any gas is,
V15 = 22.4 (1 + 15/273) = 23.63 liters per mol
Thus, at 15 °C the volume of gas produced by the explosive decomposition of one gram molecule of nitroglycerin becomes
V = 23.63 l (7.25 mol) = 171.3 liters/mo