Enthalpy of reaction

The analysis of enthalpy of reaction aims to measure the amount of heat released or absorbed during a chemical reaction. This thermodynamic data allows for the evaluation of the exothermic or endothermic nature of a process and constitutes an essential indicator for the safety, stability, and energy efficiency of industrial processes.

The study is carried out using an isothermal titration calorimeter (ITC) or an adiabatic calorimeter , depending on the type of reaction and the required precision. It provides quantitative information on:

• The heat of reaction (ΔH) ,
• The stoichiometry of the process ,
• Molecular interactions ( bonds, affinities, complexations),
• And the kinetics of the reaction .

Experimental methods and protocols

Isothermal Titration Calorimetry (ITC) directly measures the heat released or absorbed at a constant temperature during the successive addition of a reagent to a cell containing another compound.
Each injection triggers a chemical reaction, and the heat exchanged is recorded in real time.

The main parameters measured are:

• The enthalpy of reaction (ΔH) ,
• Entropy (ΔS) ,
• The bond constant (K) ,
• And the change in free energy (ΔG) .

These measurements are essential for understanding molecular interactions in complex systems, such as:

• Polymerization reactions,
• Ligand-receptor interactions (cosmetic or nutraceutical),
• Enzymatic or redox reactions,
• Neutralization or dissolution processes.

Analyses can also be carried out by adiabatic calorimetry , useful for safety and stability studies, particularly in the case of strongly exothermic reactions.

Matrices and application domains

The analysis of enthalpy of reaction applies to a wide variety of sectors:

• Cosmetics and fine chemicals : evaluation of formula stability, interactions between active ingredients and excipients.
• Agri-food and nutraceuticals : study of enzymatic, fermentative or oxidative reactions.
• Materials and polymers : monitoring of polymerization, hardening or crosslinking reactions.
• Environment and safety : identification of critical exothermic reactions in chemical processes.
• Pharmaceuticals : determination of interactions between active molecules and excipients.

Interpretation and use of results

The analysis allows us to:

• Evaluate the chemical stability of a product or mixture,
• Identify the thermal risks of an industrial process,
• Optimize reaction conditions (temperature, concentration, catalysis),
• Quantifying molecular affinities in biological or polymeric systems.

The results are generally expressed in joules per mole (J/mol) or kilojoules per mole (kJ/mol), and represented as thermal curves interpreted by our experts.

Related analyses

YesWeLab recommends combining this study with other complementary thermal and physicochemical analyses:

• Analysis of thermal degradation to assess stability before or after reaction.
• Differential scanning calorimetry (DSC) to determine phase transitions,
• Thermogravimetric analysis (TGA/ATG) to monitor mass losses associated with reactions,
• Enthalpy of vaporization to complete the energy study of physical transformations.

YesWeLab's expertise

YesWeLab relies on a network of ISO 17025 and COFRAC accredited laboratories , experts in advanced thermodynamic and calorimetric analyses .
Our engineers support industrial clients in the energy characterization of reactions , the modeling of chemical processes , and the prevention of thermal risks .

Thanks to the YesWeLab digital platform , you can:

• Order your thermodynamic studies online,
• Track the progress of your trials,
• Access your consolidated thermal results and reports