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Novel test rigs are described for the study of the corrosion of metal specimens under controlled heat fluxes. In the corrosion of stainless steels in nitric acid, tests at various heat fluxes with steel surface temperature kept constant have shown that the cooler acid present at the surface under higher heat fluxes leads to slightly smaller corrosion rates than under isothermal conditions. Crevice corrosion can develop under the gasket sealing the stainless steel specimen to the test cell. This crevice corrosion can produce enhanced corrosion rates (by factors up to 100), not only on surfaces within the crevice, but also on those external to the crevice. The factors influencing the development of crevice corrosion are discussed.

The heat capacities of (±)-butan-2-ol (crystals, glass, and liquid) and (+)-butan-2-ol (crystals and liquid) have been measured by adiabatic calorimetry at temperatures between 11 K and 350 K. Triple points and heats of fusion have been measured for both substances, and the glass transition temperature of (±)-butan-2-ol has been determined. Thermodynamic properties of the compounds have been calculated. The entropies in the ideal gas state have been compared with published values. (±)-Butan-2-ol probably forms a racemic solid solution.

Heat capacities from 12 to 400°K, heats of fusion, and triple points of pure samples of o-, m- and p-cresols have been measured by adiabatic calorimetry and used to calculate tables of thermodynamic properties. Experimental values of S°298.15 were: o-cresol (c), 39.54; m-cresol (l), 50.81; p-cresol (c), 39.99 cal deg.–1 mole–1. Values for the entropies of the cresol in the ideal gas state at 298.15 and 400°K and 1 atm pressure have also been calculated from the experimental data. Transitions with small heat changes were observed in o-cresol at 222°K and in m-cresol at 95 and 257°K.

The heat capacities of butan-2-one (I), pentan-2-one (II), pentan-3-one (III), and 3-methylbutan-2-one (IV) have been measured by adiabatic calorimetry from 12 to 320°K [360°K for (II)]. Heats of fusion and triple point temperatures were also measured. Transitions in the crystals were observed during measurements on (II) and (III). Entropies of the compounds (liquid) at 298·15°K were: (I) 239·0, (II) 274·1, (III) 266·0, and (IV) 268·5 J deg.–1 mole–1. Entropies in the ideal gas state have been calculated.

The heat capacities of 1,2,3,4-, 1,2,3,5- and 1,2,4,5-tetrafluorobenzene were measured by adiabatic calorimetry at temperatures between 11 and 353 K. Enthalpies of phase transitions were also measured. The entropies of the liquids at 298.15 K were calculated from the measurements as 256.1, 257.3 and 250.4 J K–1 mol–1 respectively. The heat capacity curve for 1,2,3,5-tetrafluorobenzene showed that a transition occurred in the crystals just below the melting temperature. 1,2,3,4-tetrafluorobenzene crystallised first in a metastable form which, on cooling, rapidly transformed to stable crystals. No anomalies were found in the heat capacity curve of 1,2,4,5-tetrafluorobenzene.

The heat capacities of five ketones [hexan-2-one (I), hexane-3-one (II), 3,3-dimethylbutan-2-one (III), 2,4-dimethylpentan-3-one (IV), and nonan-5-one (V)] have been measured. Triple-point temperatures, heats of fusion, and purities of the samples were determined. Compounds (II) and (V) were found to exist in two crystalline forms, the transitions from lower to higher temperature forms resulting in entropy increments of 4·73 and 3·39 J/K mol respectively. The entropies of the liquid ketones at 298·15 K are: (I), 308·1; (II), 305·3; (III), 282·4; (IV), 318·0; and (V), 401·4 J/K mol. The entropy of (II) at 298·15 K in the ideal-gas state was found to be 409·6 J/K mol.

The heat capacity of gold telluride, AuTe2, has been measured at 11–320 K by adiabatic calorimetry and the heat content at 367–678 K by ‘drop’ calorimetry to give S°298·15(s)=(141·7 ± 0·4) J K–1 mol–1 and for 298–737 K, Cp(s)=(63·61 + 0·03743T+ 172300/T2) J K–1 mol–1. The dissociation pressures of AuTe2 at 629–715 K have been measured by the Knudsen effusion method, and with the other data, used to calculate the heat and Gibbs energy of formation of AuTe2. ΔH°f298=(–18·6 ± 3) kJ mol–1; ΔG°f298=–17·3 kJ mol–1.

The heat capacities of pure samples of pentafluorochlorobenzene and pentafluorophenol have been measured in the condensed states over the temperature range 12–394°K. The heat of vaporization of pentafluorochlorobenzene in the pressure range ¼–1 atm. and the vapour heat capacity between 383 and 498°K have been determined. Both compounds undergo thermal transitions in the crystalline state. Heats of transition and melting were measured, and thermodynamic properties of crystals and liquid were computed. The entropies at 298·15°K of C6F5Cl (I) and C6F5OH (c) were found to be 300·7 and 227·1 J deg.–1 mole–1 respectively. Possible molecular changes associated with the thermal transitions in the solid are discussed. A value of 407·6 J deg.–1 mole–1 was found for the entropy of C6F5Cl in the ideal-gas state (at 298·15°K and 1 atm. pressure).