RICHARDS AND ROVTE. — THE SPECIFIC HEATS OF LIQUIDS. 485 



were successively placed in the calorimeter, and the flask for conduct- 

 ing the heat-producing neutralization was immersed in each just as it 

 had previously been immersed in the pure water. 



As an example, a series of results with a special solution of hydro- 

 chloric acid may be given. This acid was chosen for determination 

 because, being involved in another research, its specific heat was" a 

 matter of immediate interest. 



Below are given the data and method of calculating a single experi- 

 ment, as well as the data of a series. 



Specimen Experiment with a Solution. 



No. 3, May, 1908. 



Weight of dilute sulphuric acid in platinum bottle . 103.72 grm. 



Data concerning temperature : 



Initial temperature 16.23G° 



Final temperature 19.960° 



Temperature rise 3.724° 



Temperature of alkali 16.13° 



Excess over initial temperature —0.11° 



Heat, producing this effect : 



Calculated heat evolved by reaction = 



103.72X2169.14 2249.83 cal. (18°) 



Heat taken by alkali = 20.9 X 0.S4 X 0.11 —1.93 " 

 Total heat actually available in process . . 2247.90 cal. 



Data concerning heat capacity, in terms of water equivalent : ^^ 



Water value of calorimeter 10.87 grm. 



Water value of acid 97.50 " 



Water value of alkali 16.21 " 



Total 124.58 grm. 



Heat used by system exclusive of solution = 124.58 X 



3.724° =463.94 cal. (18°) 



Heat needed to raise 488.35 grams of hydrochloric 

 acid contained in calorimeter 



= 2247.90-463.94 = 1783.96 (18°) 



22 As these amounts are constant in all the determinations, slight constant 

 errors in them would have only a vanishingly small pernicious effect upon the 

 final results. The method is a comparatn-e one, and small errors of this kind 

 cancel out. 



