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Sonochemistry. In chemistry, the study of sonochemistry is concerned with understanding the effect of ultrasound in forming acoustic cavitation in liquids, resulting in the initiation or enhancement of the chemical activity in the solution. [1] Therefore, the chemical effects of ultrasound do not come from a direct interaction of the ultrasonic ...
Solvent effects. In chemistry, solvent effects are the influence of a solvent on chemical reactivity or molecular associations. Solvents can have an effect on solubility, stability and reaction rates and choosing the appropriate solvent allows for thermodynamic and kinetic control over a chemical reaction. A solute dissolves in a solvent when ...
In thermodynamics, an exothermic process (from Ancient Greek έξω (éxō) 'outward' and θερμικός (thermikós) 'thermal') [1] is a thermodynamic process or reaction that releases energy from the system to its surroundings, [2] usually in the form of heat, but also in a form of light (e.g. a spark, flame, or flash), electricity (e.g. a ...
In the Arrhenius model of reaction rates, activation energy is the minimum amount of energy that must be available to reactants for a chemical reaction to occur. [1] The activation energy ( Ea) of a reaction is measured in kilojoules per mole (kJ/mol) or kilocalories per mole (kcal/mol). [2] Activation energy can be thought of as the magnitude ...
Exothermic reaction. The thermite reaction is famously exothermic. The reduction of iron (III) oxide by aluminium releases sufficient heat to yield molten iron. In thermochemistry, an exothermic reaction is a "reaction for which the overall standard enthalpy change Δ H ⚬ is negative." [1] [2] Exothermic reactions usually release heat.
Sonoluminescence is the emission of light from imploding bubbles in a liquid when excited by sound. Sonoluminescence was first discovered in 1934 at the University of Cologne. It occurs when a sound wave of sufficient intensity induces a gaseous cavity within a liquid to collapse quickly, emitting a burst of light.
Sound energy. In physics, sound energy is a form of energy that can be heard by living things. Only those waves that have a frequency of 16 Hz to 20 kHz are audible to humans. However, this range is an average and will slightly change from individual to individual. Sound waves that have frequencies below 16 Hz are called infrasonic and those ...
A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. [ 1] When chemical reactions occur, the atoms are rearranged and the reaction is accompanied by an energy change as new products are generated. Classically, chemical reactions encompass changes that only involve the positions ...