silver azide vs silver fulminate gas production

dave321 - 14-8-2021 at 11:05

hi,
can anyone work out which produces the largest gas production upon detonation ?

silver azide (nitrogen and silver) or silver fulminate (co2, nitrogen? silver)

would appreciate comparative figures as i dont know how to calculate it

paulll - 14-8-2021 at 14:45

2AgN3 > 2Ag + 3N2 - ie, per mole of azide, 1.5 moles N2 produced.

2AgCNO > 2Ag + 2CO + N2 - ie, per mole of fulminate, 1 mole of CO and .5 mole N2 produced.

Given that their formula masses are nigh-on identical it looks like they pump out the same volume of gas.

Nitrosio - 16-8-2021 at 03:12

AgN3 = 4.98 g/ml
AgCNO = 3.94 g/ml

149.89 g (1 mol) = 33.62 l
224.3 l/kg (22.41 l/mol)

dave321 - 16-8-2021 at 07:47

 Quote: Originally posted by Nitrosio AgN3 = 4.98 g/ml AgCNO = 3.94 g/ml 149.89 g (1 mol) = 33.62 l 224.3 l/kg (22.41 l/mol)

can you please explain the calculation.
my A level chemistry is somewhat rusty after 46 years

Elemental Phosphorus - 16-8-2021 at 14:59

Quote: Originally posted by dave321
 Quote: Originally posted by Nitrosio AgN3 = 4.98 g/ml AgCNO = 3.94 g/ml 149.89 g (1 mol) = 33.62 l 224.3 l/kg (22.41 l/mol)

can you please explain the calculation.
my A level chemistry is somewhat rusty after 46 years

Density of silver fulminate is 3.94 grams per ml (or g/cc) and density of silver azide is 4.98 grams per ml.

Assuming the decomposition of silver proceeds as follows:
2AgN3 --> 2Ag + 3N2

And the decomposition of silver fulminate proceeds as follows:

2AgCNO --> 2Ag + 2CO + N2

Then the decomposition of one mole of silver azide or silver fulminate leads to the production of 1.5 moles of gaseous products.

One mole of any ideal gas has the same volume at a specific temperature and pressure (so 1 mole of CO and one mole of N2 take up the same space in the same conditions) and that molar volume at 1atm of pressure and 0 degrees C is about 22.4 liters. 1 mole of silver azide or silver fulminate will then make approximate 33.6 liters of gas, assuming the gas is at 0C.

Since 1 mole of silver azide weighs 149.88 grams, 1 gram of silver azide generates about 0.2242 liter of gas, or 224.2 cc.

1 mole of silver fulminate weighs approximately the same and henceforth 1 gram of the fulminate will also generate about 224.2 cc of gas.

However, since the azide is denser, 1 cc of azide will generate about 1.116 liters of gas, while 1 cc of fulminate will generate about 0.883 liters of gas.

This assumes the gas is generated at 0C, and obviously it will be hotter in an explosion, but it's a rough estimate.

[Edited on 16-8-2021 by Elemental Phosphorus]

Nitrosio - 16-8-2021 at 15:05

1.5 (1.5 N2 or 1 CO + 0.5 N2) * 22.41 = 33.62
33.62 / 149.89 * 1000 = 224.3

dave321 - 18-8-2021 at 10:16

Quote: Originally posted by Elemental Phosphorus
Quote: Originally posted by dave321
 Quote: Originally posted by Nitrosio AgN3 = 4.98 g/ml AgCNO = 3.94 g/ml 149.89 g (1 mol) = 33.62 l 224.3 l/kg (22.41 l/mol)

can you please explain the calculation.
my A level chemistry is somewhat rusty after 46 years

Density of silver fulminate is 3.94 grams per ml (or g/cc) and density of silver azide is 4.98 grams per ml.

Assuming the decomposition of silver proceeds as follows:
2AgN3 --> 2Ag + 3N2

And the decomposition of silver fulminate proceeds as follows:

2AgCNO --> 2Ag + 2CO + N2

Then the decomposition of one mole of silver azide or silver fulminate leads to the production of 1.5 moles of gaseous products.

One mole of any ideal gas has the same volume at a specific temperature and pressure (so 1 mole of CO and one mole of N2 take up the same space in the same conditions) and that molar volume at 1atm of pressure and 0 degrees C is about 22.4 liters. 1 mole of silver azide or silver fulminate will then make approximate 33.6 liters of gas, assuming the gas is at 0C.

Since 1 mole of silver azide weighs 149.88 grams, 1 gram of silver azide generates about 0.2242 liter of gas, or 224.2 cc.

1 mole of silver fulminate weighs approximately the same and henceforth 1 gram of the fulminate will also generate about 224.2 cc of gas.

However, since the azide is denser, 1 cc of azide will generate about 1.116 liters of gas, while 1 cc of fulminate will generate about 0.883 liters of gas.

This assumes the gas is generated at 0C, and obviously it will be hotter in an explosion, but it's a rough estimate.

[Edited on 16-8-2021 by Elemental Phosphorus]

hi,
i understand it now.
i failed to take into account the density of the materials.
appreciate you explaining it so clearly
thank you.

AJKOER - 29-8-2021 at 08:49

If the energy output varies, may I suspect a difference in how heated the corresponding equal gas volumes are? Energy may also be manifested as light.

In which case, these energies differentials may result in an observable difference in explosive power as well (albeit, not likely large).