Mole
Moles are the unit chemists use to count particles.
Avogadro’s number
6.02 x 1023
Empirical formula
the smallest whole-number mole ratio of the elements.
Molecular formula
the actual number of atoms of each element in one molecule or formula unit of the substance.
Precipitate
dissolved substances react to form one (or more) solid products
Coefficient
the number written in front of a reactant or product - it is a multiplier.
Synthesis reaction
two or more substances (elements and/or compounds) react to produce a single product.
A+B=AB
Single replacement reaction
the atoms of one element replace the atoms of another element in a compound.
A+BX=AX+B
Double replacement reaction
ions exchange between two compounds.
AX+BY=AY+BX
Stoichiometry
the study of quantitative relationships between the amounts of reactants used and the amounts of products formed by a chemical reaction.
Limiting reactant
limits the extent of the reaction and thereby determines the amount of product formed.
Kinetic molecular theory
explains how particles move and behave at the molecule level.
Solute vs. solvent
The dissolving medium is called the solvent. A substance that dissolves in the medium is called a solute.
What increases solubility in solutions
Stirring or shaking increases the rate of solvation, breaking the solute into small pieces increases surface area and allows more collisions to occur, as temperature increases, rate of solvation increases.
Endothermic vs. exothermic
Endothermic and exothermic are two types of chemical reactions. In an endothermic reaction, energy is absorbed from the surroundings, resulting in a decrease in temperature. In an exothermic reaction, energy is released into the surroundings, resulting in an increase in temperature.
Catalyst
something that speeds up the rate of the reaction
Reversible reaction
a chemical reaction that can occur in both the forward and reverse directions
How equilibrium shifts when changing [ ]
when products are added: shift left, when products are removed: shift right, when reactants are added: shift right, when reactants are removed: shift left
How equilibrium shifts when changing pressure/volume
when pressure increases/volume decrease: shift toward side with fewer moles
when pressure decreases/volume increases: shift toward side with more moles
How equilibrium shifts when changing temperature
exothermic: if temp increases shift left, if temp decreases shift right
endothermic: if temp increases shift right, if temp decreases shift left
K is greater than 1
Products are favored at equilibrium (there are more products than reactants)
K is less than 1
Reactants are favored at equilibrium (there are more reactants than products)
Enthalpy
the total heat content at constant pressure
Entropy
the randomness of all things in the universe.
Nuclear decay
unstable nuclei release energy by emitting radiation.
Fission vs. fusion
fission: splitting of a nucleus into fragments
fusion: combining of atomic nuclei
Alpha decay particle
4/2 He
Gamma ray charge
does not change
Beta decay particle
0/-1
Least penetrating radiation
alpha particles
Transmutation reaction
the conversion of an element into another element.