Open system
Open system
A system that can exchange both energy and matter with its surroundings.Orbital
Orbital
A region of electron density around an atom or molecule, containing no more than two
electrons of opposite spin. See Atomic orbital.
Order of reaction
Order of reaction
In a calculation of the rate law for a reaction, the sum of the exponents to which the
concentrations of reactants must be raised.
Osmosis
Osmosis
The movement of a solvent or solute through a semipermeable membrane across its
concentration gradient, i.e., from a container in which the concentration is high to a container in
which the concentration is low.
Osmotic pressure
Osmotic pressure
The pressure that must be applied to a solution to prevent the passage of a pure solvent through
a semipermeable membrane across its concentration gradient.
Oxidation
Oxidation