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This is the complete lecture note for CHM 410 Analytical Chemistry II. You can read it online below, open it in the full viewer, or download the PDF for offline study. It pairs with the course's video lectures, so you can read and watch together.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Course code: CHM 410 Course title: Analytical Chemistry II Course credit load: 2 Units Series 1: Thermal Methods Of Analysis Series 2: Electroanalytical And Potentiometric Techniques Series 3: Conductometric, Amperometric And Colorimetric Methods Series 4: Chromatographic Principles And Coupled Techniques Series 5: Radiochemical Methods In Environmental Analysis Proposed Outline Series 1 1.1 Principles of Thermal Analysis • 1.1.1 Definition and scope of thermal methods • 1.1.2 Importance and applications in analytical chemistry 1.2 Thermogravimetric and Derivative Thermogravimetric Analysis (TG and DTG) • 1.2.1 Principles of TG and DTG • 1.2.2 Instrumentation and measurement • 1.2.3 Applications and limitations 1.3 Differential Thermal Analysis (DTA) • 1.3.1 Principles of DTA • 1.3.2 Instrumentation and interpretation of curves • 1.3.3 Applications in material characterisation 1.4 Differential Scanning Calorimetry (DSC) • 1.4.1 Principles of DSC • 1.4.2 Instrumentation and data interpretation • 1.4.3 Applications in polymer and pharmaceutical analysis Introduction
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS In analytical chemistry, the study of how materials respond to changes in temperature provides valuable insights into their composition and properties. Thermal analytical techniques are widely used to investigate processes such as decomposition, phase transitions, and heat flow. These methods are essential in fields ranging from materials science to pharmaceuticals, where understanding thermal behaviour is critical for quality control and research. The aim of this Series is to introduce you to the principles and applications of thermal methods of analysis, enabling you to explain their operation, interpret their outputs, and evaluate their significance in analytical chemistry. We shall commence this Series by examining the general principles of thermal analysis, including its scope and importance. Next, we will explore thermogravimetric and derivative thermogravimetric analysis, focusing on their principles, instrumentation, and applications. Following that, we will study differential thermal analysis, considering how curves are interpreted and applied in material characterisation. Finally, we will conclude with differential scanning calorimetry, highlighting its role in polymer and pharmaceutical analysis. Series Learning Outcomes Upon completing this Series, you should be able to: • SLO 1.1 define thermal analysis and explain its scope in analytical chemistry, • SLO 1.2 describe the principles of thermogravimetric and derivative thermogravimetric analysis, • SLO 1.3 demonstrate how TG and DTG instrumentation is used to measure thermal changes, • SLO 1.4 explain the principles of differential thermal analysis and interpret DTA curves, • SLO 1.5 analyse the applications of DTA in material characterisation, • SLO 1.6 explain the principles of differential scanning calorimetry, • SLO 1.7 interpret DSC data and evaluate its applications in polymers and pharmaceuticals. 1.1 Principles Of Thermal Analysis 1.1.1 Definition and scope of thermal methods Thermal analysis refers to a group of techniques in which a property of a material is measured as a function of temperature while the material is subjected to a controlled heating or cooling programme. These methods provide information about physical and chemical changes such as phase transitions, decomposition, and heat capacity.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Thermal methods are widely used in analytical chemistry because they allow scientists to study the stability, composition, and purity of materials. They are particularly useful in materials science, pharmaceuticals, and polymer chemistry. Fill in the blank: Thermal analysis involves measuring a property of a material as a function of ______. Figure 1.1: Basic principle of thermal analysis. 1.1.2 Importance and applications in analytical chemistry The importance of thermal analysis lies in its ability to provide detailed information about material behaviour under temperature changes. For example: • It helps determine decomposition temperatures of compounds. • It identifies phase transitions such as melting or crystallisation. • It measures heat capacities and enthalpy changes. • It assesses purity and stability of pharmaceuticals and polymers. Applications include quality control in industry, research in material development, and environmental analysis of pollutants. Fill in the blank: Thermal analysis can be used to determine the ______ temperature of compounds.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Box 1.1: Selected applications of thermal analysis. Pilot questions 1.1 1. Which of the following best defines thermal analysis? a. Measurement of a property of a material as a function of temperature b. Measurement of a property of a material as a function of pressure c. Measurement of a property of a material as a function of concentration d. Measurement of a property of a material as a function of volume 2. Fill in the blank: Thermal analysis involves measuring a property of a material as a function of ______. 3. Which of the following is an application of thermal analysis? a. Determining decomposition temperatures b. Measuring electrical conductivity c. Studying light absorption spectra d. Measuring magnetic susceptibility 4. Fill in the blank: Thermal analysis can be used to determine the ______ temperature of compounds. 5. Which of the following industries commonly uses thermal analysis? a. Pharmaceuticals b. Agriculture c. Textile design d. Astronomy 1.2 Thermogravimetric And Derivative Thermogravimetric Analysis (TG And DTG) 1.2.1 Principles of TG and DTG Thermogravimetric analysis (TG) is a technique in which the mass of a sample is measured as it is heated, cooled, or held at a constant temperature. It provides information about changes such as decomposition, oxidation, or loss of volatile components. Derivative thermogravimetry (DTG) is the first derivative of the TG curve with respect to time or temperature. It highlights the rate of mass change, making it easier to identify overlapping processes and pinpoint exact transition temperatures. Fill in the blank: Derivative thermogravimetry is the first ______ of the TG curve with respect to time or temperature.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Figure 1.2: TG and DTG curves. 1.2.2 Instrumentation and measurement TG instruments typically consist of a precision balance, a furnace, and a temperature control system. The sample is placed on the balance inside the furnace, and its mass is continuously recorded as the temperature changes. In DTG, the instrument software calculates the derivative of the TG curve, producing peaks that correspond to specific thermal events. This allows clearer identification of processes such as moisture loss, decomposition, or oxidation. Fill in the blank: A TG instrument usually consists of a balance, a furnace, and a ______ control system. Plate 1.2: Basic TG instrumentation. 1.2.3 Applications and limitations TG and DTG are widely applied in analytical chemistry: • Determining thermal stability of materials. • Measuring moisture and volatile content.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS • Studying decomposition pathways of polymers and pharmaceuticals. • Investigating oxidation and reduction behaviour of metals. However, limitations include sensitivity to sample size, potential overlapping of thermal events, and the need for careful calibration to ensure accuracy. Fill in the blank: TG and DTG can be used to measure the ______ content of a sample. Box 1.2: Applications of TG and DTG. Pilot questions 1.2 1. Which of the following best defines thermogravimetric analysis? a. Measurement of mass change of a sample with temperature b. Measurement of heat flow of a sample with temperature c. Measurement of pressure change of a sample with temperature d. Measurement of colour change of a sample with temperature 2. Fill in the blank: Derivative thermogravimetry is the first ______ of the TG curve with respect to time or temperature. 3. Which of the following components is part of a TG instrument? a. Balance b. Microscope c. Spectrophotometer d. Electrode 4. Fill in the blank: A TG instrument usually consists of a balance, a furnace, and a ______ control system. 5. Which of the following is a limitation of TG and DTG? a. Sensitivity to sample size b. Ability to measure moisture content c. Ability to study decomposition pathways d. Ability to investigate oxidation behaviour 1.3 Differential Thermal Analysis (DTA) 1.3.1 Principles of DTA Differential thermal analysis (DTA) is a technique in which the temperature difference between a sample and a reference material is measured as both are subjected to the same heating
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS or cooling programme. Any thermal event in the sample, such as melting, crystallisation, or decomposition, produces a peak on the DTA curve. This method is particularly useful for identifying phase transitions and comparing thermal behaviour between different materials. Fill in the blank: In DTA, the temperature difference between a sample and a ______ material is measured. Figure 1.3: Principle of differential thermal analysis 1.3.2 Instrumentation and interpretation of curves A DTA instrument consists of a furnace, a sample holder, a reference holder, and thermocouples to measure temperature differences. The sample and reference are heated simultaneously, and the thermocouples record any deviation in temperature. The resulting DTA curve shows endothermic peaks (heat absorbed, e.g. melting) and exothermic peaks (heat released, e.g. crystallisation). The position and shape of these peaks provide information about the type and magnitude of thermal events.
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