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Solution equilibrium
When a solute is dissolved in a solvent, it will dissociate until reaching an equilibrium point at which the rate of dissociation equals the rate of precipitation of the solute, regardless of any additional solute introduced into the mixture
solvation
sol, a chemical process in which solvent molecules and molecules or ions of the solute combine to form a compound
Solvent
substance in which a solute is dissolved to form a solution
Acid dissociation constant
An equilibrium expression used to measure weak-acid strength, given by the ratio of the product of the products' molar concentrations to the product of the reactants' molar concentrations, with each term raised to the power of its stoichiometric coefficient. Denoted Ka.
Amphoteric
having characteristics of both an acid and a base and capable of reacting as either
Common ion effect
The molar solubility of one salt is reduced when another salt, having a common ion is brought into the same solution
Molar solubility
The molar amount of a solute that can dissolve in 1L of solvent until equilibrium-saturation-is reached
Arrhenius Definition
defined acids as subtsances that produced H ions in water, while bases produced OH ions. When they reacted together, H and OH neutralise to make water
Bronsted-Lowry definition
Common definition of acids as proton (H+) donors and bases as proton acceptors
Buffer
an ionic compound that resists changes in its pH
Conjugate acids and Bases
Systematic pairing of a deprotonated species (base) with its protonated form (conjugate acid). Conjugates appear on opposite sides of a chemical equation.
Diprotic Base
A base that can accept two moles of H+ per mole of itself (ex: SO₄²-).
Equivalence point
The point during a titration when the number of H+ ions and OH- ions are equal. This is at the middle of the steepest part of the titration curve.
Azeotrope
mixture of 2 or more substances that distills at a constant temperature and with constant composition, even though seperately the components have different boiling points
Colligative properties
A physical property of a solution that depends on the number, but not the identity, of the disswolved solute particles; example properties include vapor pressure lowering, boiling point elevation, osmotic pressure, and frezzing point depression
Phase diagram
a graph of pressure versus temperature that shows the conditions under which the phases of a substance exist
Ion
an atom, radical, or molecule that has gained or lost one or more electrons and has a negative or positive charge
Ion product
Product of the molar concentrations of dissociated ions in solution at any point in the reaction other than equilibrium or saturation, where each ion is raised to the power of its stoichiometric coefficient. Denoted IP.
Molality
The ratio of the number of moles of solute dissolved in one kilogram of solvent. molality (M = moles solute/kg of solution)
Alkaline earths
Slightly less reactive than alkali metals, comprise group II
Graham's Law
temperature is constant; effusion and temperature are proportional to the square root of their masses
Effusion
The process by which a gas escapes from one container to another at lower pressure through a tiny hole in the container.
Raoult's Law
The vapor pressure of solution is the product of the mole fraction of the solvent and the vapor pressure of the pure solvent. P_a=X_aP_total
Nucleus
the center of the atom which contains the protons and neutrons; in cells, structure that contains the cell's genetic material (DNA) and controls the cell's activities
Net ionic equation
A representation of a displacement reaction showing only the reactive species and omitting the spectator ions.
Percent composition
The Percent by mass of each element in a compound.
Percent yield
the ratio of the actual yield to the theoretical yield for a chemical reaction expressed as a percentage; a measure of the efficiency of a reaction
single displacement reaction
a reaction in which atoms of one element take the place of atoms of another element in a compound
Theoretical yield
the amount of product that can be made in a chemical reaction based on the amount of limiting reactant
Titration
a measured amount of a solution of unknown concentration is added to a known volume of a second solution until the reaction between them is just complete
Water dissociation Constant
Expression of auto-ionization of water into H+ and OH-at a certain temperature, given by the product of the ions' molar concentrations. Denoted by Kw and equal to 10-¹⁴ at 25˚C. Kw = [H+][OH-]
Dispersion Forces
attractions between molecules caused by the electron motion on one molecule affecting the electron motion on the other through electrical forces; these are the weakest interactions between molecules
Formal Charge
Charge assigned to an atom in a molecule or polyatmic ion, calculated by (# valence electrons) - (# 1/2 bonding electrons) - (# nonbonding electrons). Molecules containing atoms with lower formal charges tend to be more stable than those with higher formal charges.
Hydrogen bonding
the intermolecular force in which a hydrogen atom that is bonded to a highly electronegative atom is attracted to an unshared pair of electrons of an electronegative atom in a nearby molecule
Intermolecular forces
Attractive and repulsive forces between molecules that are weaker than forces within molecules.
Ionic Bond
a chemical bond in which one atom loses an electron to form a positive ion and the other atom gains to electron to form a negative ion
Half equivalence point
where half of the acid is neutralized by the base on a titration curveAn acid dissociation constant, Ka, (also known as acidity constant, or acid-ionization constant) is a quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction known as dissociation in the context of acid-base reactions. The equilibrium can be written symbolically as: HA A− + H+, where HA is a generic acid that dissociates by splitting into A−, known as the conjugate base of the acid, and the hydrogen ion or proton, H+, which, in the case of aqueous solutions, exists as a solvated hydronium ion.
Nonpolar covalent bond
A covalent bond in which the bonding electrons are shared equally by the bonded atoms, resulting in a balanced distribution of electrical charge
Octet Rule
atoms react by gaining or losing electrons so as to acquire the stable electron structure of a noble gas, usually eight valence electrons
Atomic weight
The weight in grams of one mole of a given elementand is expressedin tems of grams per mole.
Avagadros number
the number of atoms in exactly 12 g of pure 12c and equal to 6.022 x 10^23 is called
atomic theory
(chemistry) any theory in which all matter is composed of tiny discrete finite indivisible indestructible particles
quanta
Small discrete increments of energy.
quantum
(physics) the smallest discrete quantity of some physical property that a system can possess (according to quantum theory) E=hf
Planck's Constant
A fundamental constant, h, that relates the energy of light quanta to their frequency: h = 6.6 X 10^-34 joule·second
The bohr model
1913, Niels Bohr, said that electrons formed specific layers instead or random ones, said atoms atoms absorb and give off energy when the electrons move from one shell to another
angular momentum in the bohr model
nh/2π The angular momentum changes only in discete amounts with respect to the quantum number. Also E=-R_h
Rydberg constant
2.18 x 10^-18 J/electron
Ground state
the lowest allowable energy state of an atom
electromagnetic energy of photons emmited from electrons at ground state
E=hc/λ
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