Basic Knowledge Needed for AP Chemistry and the AP Exam.
What is a solution?
A homogeneous mixture made up of two or more substances that do not chemically combine; instead, the substances mix uniformly in the solution.
What is a solvent?
The substance present in the largest quantity by volume, usually water.
What is a solute?
The substance that is dissolved in the solvent.
How do you find the empirical formula of a compound?
First, determine mol by dividing the percent comp or mass of elements by their molar mass, then divide the mol values by the smallest mol value.
How do you find the molecular formula of a compound?
First, determine the mass of the empirical formula, then divide the mass of the molecular formula by the mass of the empirical and finally multiply the empirical formula by the ratio obtained between the masses.
Are compounds of Group 1 metals soluble or insoluble?
Are common ammonium ions soluble or insoluble?
Are common nitrates soluble or insoluble?
Are common acetates soluble or insoluble?
Are common chlorates soluble or insoluble?
Are common perchlorates soluble or insoluble?
List the insoluble fluoride compounds.
MgF₂, CaF₂, SrF₂, BaF₂, PbF₂
List the insoluble halide compounds.
AgX, Hg₂X, PbX₂
What is the molarity equation?
M = mol/Liters
What is the dilution equation?
M₁V₁ = M₂V₂
The formation of an insoluble compound in an aqueous solution.
The insoluble compound formed out of precipitation.
What are cations?
Positively charged ions.
What are anions?
Negatively charged ions.
What is the ideal gas law equation?
PV = nRT
What is the value of 'R' in the ideal gas law when using atm?
What is effective nuclear charge?
A measure of the nuclear charge experienced by an atom, meaning as the effective nuclear charge increases for electrons they will be pulled closer to the nucleus.
What is ionization energy?
The amount of energy required to remove an electron from a gaseous atom or ion, forming a positive-charged ion.
How is ionization energy related to atomic radius?
Ionization energy increase as atomic radius decreases and decreases as atomic radius increases.
What is electron affinity?
A measure of the energy change present when gaseous atoms take electrons into their valence shells, creating negatively-charged ions.
What is an oxidation reduction reaction?
A reaction that occurs with the transfer of electrons from one species to another.
What is a reduction in an oxidation-reduction reaction?
The result of gaining electrons, causing a reduction in oxidation number.
What is an oxidation in an oxidation-reduction reaction?
The result of losing electrons, causing an increase in oxidation number.
What is an oxidation number?
A number that represents the ionic charge of an ion.
What is a reducing agent (reductant)?
The species in a oxidation-reduction reaction that loses electrons, gaining a positive charge, to reduce the other species.
What is an oxidizing agent (oxidant)?
The species in an oxidation-reduction reaction that gains electrons from the reductant, giving it a negative charge.
What is a voltaic cell?
A device that allows the transfer of electrons between the reactants of an oxidation-reduction reaction without contact between the reactants.
What is an electrode?
A sample of metal that is connected to another by an external circuit.
Briefly explain the collision theory.
Suggests that chemical reaction occur when molecules or atoms collide with sufficient kinetic energy-the activation energy-and the collision occurs in a favorable orientation.
Who was the first to suggest the collision theory?
Svante Arrhenius in 1888.
Define reaction rate.
The change in amount of substance as it disappears or the other appears (measured in mol) divided by the elapsed time.
What changes the rate constant?
What is the rate law equation?
rate = k[A][B]
How can you determine reaction orders?
What are reaction mechanisms?
The steps that occur during a chemical reaction as the reactants change into products.
What is an elementary step?
A process in a chemical reaction that only involves a single step.
Write an equilibrium expression.
Kc = ([C][D]/[A][B])
Explain Le Châtelier's Principle.
If a system at equilibrium is disturbed by a change in temperature, pressure or reactant or concentrations, then the system will respond by shifting its equilibrium position to counteract the effect of the disturbance.