An Adiabatic Solution Calorimeter and Measurements of a Standard Reaction for Solution Calorimetry.

Abstract

This paper discusses in detail the design, construction, and performance of the vacuum jacketed, adiabatic solution calorimeter which was used for the work in the certification of two NBS Standard Reference Materials for solution calorimetry. As a test for the calorimetric precision the following enthalpies of reaction were measured (referred to the mass or moles of H2SO4 · 8H2O): H 2 S O 4 ⋅ 8 H 2 O + 2.36 ( N a O H ⋅ 2620 H 2 O ) = ( N a 2 S O 4 ⋅ 0.36 N a O H ⋅ 6193 H 2 O ) soln Δ H r ( 298.15 K ) = - 590.692 ± 0.101 J ⋅ g - 1 = - 34 , 194.1 ± 5.9 cal ⋅ mol - 1 H 2 S O 4 ⋅ 8 H 2 O + 2.6 ( N a O H ⋅ 714 H 2 O ) = ( N a 2 S O 4 ⋅ 0.6 N a O H ⋅ 1866 H 2 O ) soln Δ H r ( 298.15 K ) = - 590.828 ± 0.193 J ⋅ g - 1 = - 34 , 203.4 ± 11.1 cal ⋅ mol - 1 .