Sulfate of Ammonia 15 



piece of cheese cloth placed over the thistle 

 tube. The reaction results in the precipi- 

 tation of calcium carbonate in the flask, 



Ca02H2 + (NH4)2C03 = CaCOa + 2NH3 

 + 2H2O, 



and the liberation of ammonia which vola- 

 tilizes faster than the ammonium carbonate. 



When the sulfuric acid is entirely neutra- 

 lized, as is shown by the action of litmus 

 paper or a decided change in the appearance 

 of the distillate, disconnect the apparatus. 

 Filter the solution of ammonium sulfate in 

 the gas bottle if tariy matter has collected in 

 it, first making sure that all the ammonium 

 sulfate is in solution, and evaporate the clear 

 filtrate in a porcelain dish to the point of 

 crysta'lization. 



Cool the mixture, bring the mass of crystals 

 on a paper filter and allow them to drain and 

 further dry by pressing between filter papers. 

 Weigh the crystals and enter the amount in 

 the notebook. 



To become familiar with the properties of 

 the salt, heat a little in a dry test tube and 

 hold a piece of moistend red litmus in the 

 mouth of the tube. Ammonium sulfate 

 melts at 140°; at 280° it decomposes, losing 

 ammonia and leaving behind ammonium 

 acid sulfate. 



