The chapter explores the effects of reaction kinetics on differential thermal analysis (DTA) patterns, specifically for reactions of the type solid → solid + gas. The author, Homer E. Kissinger, uses analytical methods to construct curves of reaction rate versus temperature for constant heating rates, demonstrating how varying reaction orders influence peak positions. This information is applied to analyze DTA patterns of magnesite, calcite, brucite, kaolinite, and halloysite, with results agreeing with isothermal studies except in specific cases. The chapter discusses the relationship between peak temperature and reaction rate, assuming that the peak in DTA occurs when the reaction rate is maximum. It derives equations to describe the temperature distribution in the sample holder and the peak temperature, which depends on the reaction order. The peak shape and asymmetry are analyzed, and a "shape index" is proposed to quantify asymmetry. This index is shown to be a function of the reaction order. Experimental procedures are outlined, including the use of platinum specimen holders and α-aluminum oxide as a reference material. The study examines magnesite, calcite, brucite, kaolinite, and halloysite, and compares DTA results with isothermal weight-loss data. The agreement between DTA and isothermal methods is generally good, though some discrepancies are noted, particularly for calcite and brucite. The conclusions highlight that DTA can provide valuable kinetic information about simple decomposition reactions, with the dominant factor controlling peak shape and position being the nature of the reaction itself. Factors such as particle size, dilution, and pressure are not yet fully explored but are recognized as potential influences.The chapter explores the effects of reaction kinetics on differential thermal analysis (DTA) patterns, specifically for reactions of the type solid → solid + gas. The author, Homer E. Kissinger, uses analytical methods to construct curves of reaction rate versus temperature for constant heating rates, demonstrating how varying reaction orders influence peak positions. This information is applied to analyze DTA patterns of magnesite, calcite, brucite, kaolinite, and halloysite, with results agreeing with isothermal studies except in specific cases. The chapter discusses the relationship between peak temperature and reaction rate, assuming that the peak in DTA occurs when the reaction rate is maximum. It derives equations to describe the temperature distribution in the sample holder and the peak temperature, which depends on the reaction order. The peak shape and asymmetry are analyzed, and a "shape index" is proposed to quantify asymmetry. This index is shown to be a function of the reaction order. Experimental procedures are outlined, including the use of platinum specimen holders and α-aluminum oxide as a reference material. The study examines magnesite, calcite, brucite, kaolinite, and halloysite, and compares DTA results with isothermal weight-loss data. The agreement between DTA and isothermal methods is generally good, though some discrepancies are noted, particularly for calcite and brucite. The conclusions highlight that DTA can provide valuable kinetic information about simple decomposition reactions, with the dominant factor controlling peak shape and position being the nature of the reaction itself. Factors such as particle size, dilution, and pressure are not yet fully explored but are recognized as potential influences.