Essential Definitions and Laws of Physical Chemistry
pure substance is a phase of uniform composition and invariant Q can not be broken by physical methods salt, alcohol .. Q elements pure substances can not separate x chemical methods: hydrogen, nitrogen compound.
. Pure substances made up of 2 or more elements and Q can be separated by chemical methods: marble, sucrose ..
mix is an aggregation of different substances Q occur without any reaction between them both can kimica separate x x physical methods. Ls atoms are called isotopes of the element
Q msmo present different content into neutrons and therefore no distinct mass. Estaformada electromagnetic radiation
Q waves move at the speed of light, this is related to the wavelength and frequency:
C = ? · v.
wavelength is the distance between two peaks I Two successive minima of a wave. His usual unit is the meter aunk tb can be expressed in centimeters, nanometers 1nm = 10 *- 9m, and 1A = 10 *- angstroms 10m.
Frequency is the number of oscillations Q PSAN for point in unit time unit is normally s *- 1 Q tb hertzioHz an oscillation is called a vibration that gives rise to a wave length ?. Q is the time period it takes the wave to travel one wavelength is expressed in units of time usually segundos.T = 1 / v Number of waves is the number of oscillations a and Q per unit length is unity m *- 1.The electromagnetic spectrum is the set of radiation qimico link electromagneticas.El is due to the existence of forces Q attractive atoms held together in an ionic compound, covalent or metallic.
dissociation energy is the energy needed to break a bond formado.Si atoms bonded to communicate an energy equal to or greater horn get away completely separate Q does not exercise such interactions each other.
ionic bond is produced by binding an element of metallic character (on the table izkierda) cn metal one does not (on the Derex) the link form a crystal lattice.
covalently joining occurs between two elements if of a non-metallic (located on the table Derex) TB are covalent bonds in the Q of the element hydrogen is not attached to the metal type (made sharing electrons.)
metallic bond is responsible for the union of atoms metals among themselves, these atoms are grouped very close to each other as Q estruccturas produces very compact (crystal lattices).
intermolecular forces in covalent molecules can exert on each type electrostatic attractive forces.
metallic bond is responsible for the union of metal atoms between them, these atoms are grouped very close to each other as Q estruccturas produces very compact (crystal lattices).
intermolecular forces in covalent molecules can exert on each type electrostatic attractive forces. LAWS WEIGHT:
law of conservation of mass mass is neither created nor destroyed only transformed (mass of reactants is the mass of products) lavoisier.
law of constant proportions or defined proust compound always has the same elements and in the same proportions regardless of the process followed in its formation or where 2 or more elements combine to form a compound Kimicar always acen a constant ratio between masses.
law of multiple proportions if a quantity of an element A (a) is combined with fixed amounts of another element B b1 and b2 to give 2 different compounds X and Y the relation in Q are the quantities b1 and b2 is the numbers simple whole.
law of combining volumes and volumes of reacting gases produced bear a simple numerical relationship as long as they work to P and t º cte.Avogadro’s hypothesis [concept of molecule]:
equal volumes of different gases contain the Q demoleculas always the same number of volumes have been measured under the same conditions of P and t º.
mole is the amount of substance ek Q contains the same number of elementary entities in 0.012kg of Q ay carbono12.
amu is defined as the amount in grams ekivalente the mass of one twelfth of the atom of carbon 12.
Boyle law keeping the temperature constant the product of pressure by the volume of a certain mass of gas is PV = cte cte.
charles law at constant pressure the volume varies in direct relation to the temperature expressed in kelvin V1/T1 = V2/T2.
law of Gay Lussac pressure at constant volume varies directly with the temperature expressed in kelvin P1/T1 = P2/T2.3leyes
Clapeyron the
PV = nRT.La formula of the compounds or polyatomic molecules is the simplest symbolic representation of one part mismos.Expressa Q atoms form said compound and the other the amount involved in these Q.