For an explanation, see the main splats page
SPLATS about rates of reaction
The principles of rates of reaction
- Every reaction proceeds until an equilibrium point is reached. Depending on other conditions, this may be reached rapidly or slowly, but it can be influenced.
- Chemical equilibrium is always a dynamic equilibrium, with changes in one reaction direction being influenced by changes the other way restoring the status quo.
- The study of chemical equilibrium is an important part of chemistry because most chemical reactions proceed only to equilibrium and halt after that is reached.
- The equilibrium point often changes with physical conditions such as the operating temperature, pressure, and the concentrations of reactants.
- The speed of a reaction to equilibrium changes with physical conditions such as temperature, pressure, and the surface areas and concentrations of reactants.
- Chemical changes occur at different speeds, which can be affected by the presence of a catalyst, which affects the rate of reaction, but is not changed.
- A catalyst is something which influences the rate at which a chemical reaction proceeds to equilibrium, but which is not itself changed by the reaction.
- A catalyst can be used to increase the speed at which an equilibrium is reached, but the catalyst does not influence the actual equilibrium point in any way.
- Enzymes operate as catalysts best under very specific conditions of temperature and acidity, and they can all be destroyed by high temperatures.
- Enzymes are found in all living things: they are proteins, catalysts that are coded for by individual genes. They control all biochemical pathways in the cell.
- An enzyme is a protein which operates in a biochemical reaction in the same way as a catalyst in a chemical reaction, and like a catalyst, remains unchanged.
- Every chemical reaction is associated with an equilibrium constant, which may be predicted with reasonable accuracy, using standard known values.
- In 1803, Claude Berthollet stated that the proportions of the reactants affects the direction in which chemical reactions take place, changing the equilibrium.
- The speed of a reaction varies with the surface area of the reactants, as this increases the frequency of particle contact, increasing the chances for reaction.
- The reaction of an equilibrium to changes in physical conditions is described by Le Chatelier's principle: the equilibrium moves to accommodate the changes.
- The equilibrium point of a chemical reaction may be influenced by changing the physical factors like heat and pressure to favour one reaction over another.
- In 1876, Josiah Gibbs began writing on phase equilibria, the free energy as the driving force behind chemical reactions, and chemical thermodynamics in general.
- Some chemical reactions only take place if the energy barrier is overcome by heat or a catalyst: once started the reaction provides the energy to keep it going.
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