474 DIAZO COMPOUNDS AND OTHERS. 



9. NITRIC ACID AND DINITROBENZENE. 



1. The reaction of total combustion is 



C 6 H 4 N 2 4 + 4N0 3 H = 6C0 2 + 4H 2 + 3N 2 . 



2. The proportions by weight are, 168 grms. of dinitrobenzene 

 to 252 grms. of acid ; in all, 420 grms. ; or, for 1 kgm., 400 grms. 

 of dinitrobenzene and 600 grms. of acid. Note that the 

 dinitrobenzene is crystallised. 



3. The heat liberated will be, for 1 equiv., 387'4 Cal. (liquid 

 water), or 347'4 Cal. (gaseous water); or, for 1 kgm., 899 Cal., 

 or 827 CaL 



4. The reduced volume of the gases, for 1 equiv., 201 litres 

 (liquid water), or 290 litres (gaseous water); or, for 1 kgm., 

 479 litres, or 690 litres. 



479 atm. 



5. The permanent pressure = - . 



n U'lo 



10800 atm. 



6. The theoretical pressure = > with the usual 



n 



reservation. 



It is nearly identical with that of nitrobenzene. This is as 

 it should be, the heat liberated and the reduced gaseous volume 

 being nearly the same for equal weights. With picric acid the 

 difference is also slight. On the whole, all these mixtures are 

 very inferior in theory to nitroglycerin or gun-cotton. The 

 corrosive properties of nitric acid must, moreover, render 

 difficult the transport of mixtures made beforehand. Lastly, 

 the stability of such mixtures is more than doubtful. But they 

 have this advantage, that they can be prepared on the spot and 

 instantaneously. 



10. PERCHLORIC ETHERS. 



1. The ethers of the highly oxygenated acids are probably 

 explosive, but the only ones which have so far been prepared 

 are the perchloric ethers. These are, in fact, eminently explosive 

 bodies. The thermal and mechanical properties of methyl- 

 perchloric ether, the only one corresponding to a total com- 

 bustion among the ethers of monatomic alcohols, will be given. 



2. The formula for methylperchloric ether is the following : 



CH 2 (C10 4 H). 

 It corresponds to the equivalent 114*5. 



3. The explosive decomposition will be 



CH 2 (C10 4 H) = C0 2 + H 2 + HC1 + 0. 



It will be seen that it sets free an excess of oxygen, like 

 nitroglycerin and nitromannite. 



4. The heat of formation of methylperchloric ether, from the 



