Physical chemistry
Mikhail Lomonosov stood before students at Petersburg University in 1752 to deliver a lecture course titled A Course in True Physical Chemistry. He defined the field as the science that must explain under provisions of physical experiments the reason for what is happening in complex bodies through chemical operations. This early definition established physical chemistry as the study of macroscopic and microscopic phenomena in chemical systems using principles like motion, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics, analytical dynamics, and chemical equilibria. The discipline distinguishes itself from chemical physics by focusing predominantly on supra-molecular science rather than atomic or molecular structure alone. Most foundational principles relate to bulk properties such as chemical equilibrium and colloids instead of individual atoms. Relationships between intermolecular forces and material properties like plasticity, tensile strength, and surface tension in liquids form core areas of inquiry. Reaction kinetics determine how fast processes occur while ion identity affects electrical conductivity of materials. Surface science and electrochemistry examine cell membranes alongside interactions involving heat and work called thermodynamics. Transfer of heat during phase changes or reactions defines thermochemistry while colligative properties describe species numbers in solution. Phase rules correlate number of phases with components and degree of freedom known as variance. Reactions within electrochemical cells follow predictable patterns based on these underlying physical laws.
Quantum chemistry applies quantum mechanics to chemical problems to determine bond strength and shape along with nuclear movement. Light absorption or emission by a compound becomes measurable through spectroscopy which interacts electromagnetic radiation with matter. Chemical thermodynamics sets limits on reaction progress and energy conversion into work for internal combustion engines. Thermal expansion coefficients link to entropy rate changes with pressure for gases or liquids. Quasi-equilibrium and non-equilibrium thermodynamics describe irreversible changes though classical thermodynamics focuses mostly on systems in equilibrium and reversible changes. Chemical kinetics examines transition states higher in energy than reactants or products that serve as barriers to reaction. Higher barriers result in slower reactions while elementary sequences each possess their own transition state. Temperature and concentration dependencies dictate reaction rates alongside catalyst engineering to optimize outcomes. Statistical mechanics explains why large particle mixtures like those containing Avogadro constant 6 x 10^23 particles can be described by few variables such as pressure, temperature, and concentration. Engineers rely on these predictions without needing every molecule position or speed data. Everyday life properties emerge from molecular characteristics without empirical correlations based solely on chemical similarities.
Josiah Willard Gibbs published his paper On the Equilibrium of Heterogeneous Substances in 1876 introducing cornerstones like Gibbs energy, chemical potentials, and phase rule. Wilhelm Ostwald and Jacobus Henricus van 't Hoff founded Zeitschrift für Physikalische Chemie in 1887 as the first scientific journal dedicated to physical chemistry. Svante August Arrhenius joined them as leading figures during the late nineteenth century and early twentieth century. All three received Nobel Prizes in Chemistry between 1901 and 1909 for their contributions. Irving Langmuir advanced work on colloids and surface chemistry over subsequent decades. Linus Pauling emerged as a leading name when quantum mechanics developed into quantum chemistry starting in the 1930s. Infrared spectroscopy, microwave spectroscopy, electron paramagnetic resonance, and nuclear magnetic resonance spectroscopy became important experimental methods throughout the twentieth century. Isotope separation discoveries before and during World War II contributed significantly to nuclear chemistry developments. Astrochemistry research continues expanding boundaries while calculation algorithms enable precise property predictions from chemical structure alone. Boiling point, critical point, surface tension, vapor pressure, and more than twenty other properties can be calculated without synthesizing molecules.
Spectroscopic techniques allow scientists to observe electromagnetic radiation interactions with matter at molecular levels. Infrared spectroscopy identifies functional groups within compounds through vibrational transitions detected by infrared light absorption. Microwave spectroscopy measures rotational energy states of gas-phase molecules with high precision. Electron paramagnetic resonance detects unpaired electrons in free radicals or transition metal complexes. Nuclear magnetic resonance spectroscopy maps atomic environments inside complex organic structures using radiofrequency pulses. These tools provide data necessary for validating theoretical models derived from statistical mechanics. Computational algorithms now calculate additive physicochemical properties directly from structural formulas without physical synthesis. Group contribution methods like Lydersen method, Joback method, and Benson group increment theory estimate boiling points and vapor pressures accurately. Quantitative structure, activity relationships predict biological effects based on molecular geometry and electronic distribution. Modern software packages integrate these calculations into drug design pipelines where unsynthesized candidates undergo virtual screening. Researchers verify experimental results against predicted values before committing resources to actual laboratory work. This approach saves time and materials while accelerating discovery cycles across pharmaceuticals and materials science industries.
Zeitschrift für Physikalische Chemie launched in 1887 as the inaugural publication dedicated exclusively to physical chemistry research. Journal of Physical Chemistry began publishing in 1896 before renaming itself Journal of Physical Chemistry A in 1997. Physical Chemistry Chemical Physics started operations in 1999 evolving from Faraday Transactions which dated back to 1905. Macromolecular Chemistry and Physics entered the field in 1947 focusing on large molecule systems. Annual Review of Physical Chemistry commenced publication in 1950 summarizing major advances each year. Molecular Physics journal appeared in 1957 bridging physics and chemical applications. Journal of Physical Organic Chemistry opened its doors in 1988 addressing organic reaction mechanisms through physical lenses. Journal of Physical Chemistry B followed in 1997 expanding coverage beyond original scope. ChemPhysChem emerged in 2000 combining two distinct areas under one banner. Journal of Physical Chemistry C arrived in 2007 concentrating on condensed matter phenomena. Journal of Physical Chemistry Letters began distribution in 2010 merging previously separate letter publications into a single rapid communication outlet. Annales de chimie et de physique operated continuously from 1789 until 1914 covering both disciplines together historically.
Common questions
What is physical chemistry and how did Mikhail Lomonosov define it in 1752?
Physical chemistry is the science that explains phenomena in complex bodies through chemical operations using principles like motion, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics, analytical dynamics, and chemical equilibria. Mikhail Lomonosov defined the field as such when he delivered a lecture course titled A Course in True Physical Chemistry at Petersburg University on the 1st of January 1752.
Who founded Zeitschrift für Physikalische Chemie and when was it established?
Wilhelm Ostwald and Jacobus Henricus van 't Hoff founded Zeitschrift für Physikalische Chemie in 1887 as the first scientific journal dedicated to physical chemistry. Svante August Arrhenius joined them as leading figures during the late nineteenth century and early twentieth century before all three received Nobel Prizes in Chemistry between 1901 and 1909 for their contributions.
How does quantum chemistry apply quantum mechanics to determine bond strength and shape?
Quantum chemistry applies quantum mechanics to chemical problems to determine bond strength and shape along with nuclear movement by analyzing light absorption or emission measurable through spectroscopy which interacts electromagnetic radiation with matter. This approach allows scientists to observe electromagnetic radiation interactions with matter at molecular levels to validate theoretical models derived from statistical mechanics.
What are the core areas of inquiry regarding intermolecular forces and material properties?
Relationships between intermolecular forces and material properties like plasticity, tensile strength, and surface tension in liquids form core areas of inquiry within physical chemistry. The discipline distinguishes itself from chemical physics by focusing predominantly on supra-molecular science rather than atomic or molecular structure alone while examining bulk properties such as chemical equilibrium and colloids instead of individual atoms.
Which journals were launched to publish research in physical chemistry starting from 1876?
Josiah Willard Gibbs published his paper On the Equilibrium of Heterogeneous Substances in 1876 introducing cornerstones like Gibbs energy, chemical potentials, and phase rule before Zeitschrift für Physikalische Chemie launched in 1887 as the inaugural publication dedicated exclusively to physical chemistry research. Journal of Physical Chemistry began publishing in 1896 before renaming itself Journal of Physical Chemistry A in 1997 while Annales de chimie et de physique operated continuously from 1789 until 1914 covering both disciplines together historically.