physical change
change to appearance without changing identity (intermolecular forces are broken and new ones are formed; crush, boil, melt)
chemical change
change that transforms one substance into a different substance (chemical bonds are broken and new ones are formed; burning, decomposing)
chemical reactions
represented through chemical equations.
save elements that appear in multiple products/reactants for last (usually O or H)
keep conserved polyatomic ions together
balance 1 element at a time
a. the number and type of atoms remain the same, but their arrangement changes when going through a reaction
molecular equation
ionic compounds always expressed as neutral compounds
complete ionic equation
the ions of aqueous compounds are written out individually (keep solids, liquids, and gases together)
net ionic equation
like complete ionic equation, but removes spectator ions that don’t react (aqueous compounds on both sides are removed)
limiting reactant
determines how much product you can make based on the quantities of reactants
combination (synthesis) reaction
A + B → AB
decomposition reaction
AB → A + B
single-replacement reaction
AB + C → AC + B
double-replacement reaction
AB + CD → AD + BC
(generally) nonreactive metals
copper, silver, mercury, platinum, and gold generally don’t like being in a compound, and often react to become a solid metal
bronsted-lowry acid
acids “donate” a hydrogen ion (proton) to bases
HCl + NaOH → NaCl + H2O
bronsted-lowry base
bases accept a hydrogen ion (proton) from acids
conjugate acid
results when a base accepts a proton
conjugate base
results when an acid donates its proton
amphoteric molecules
can act as either an acid or base (H2O, HCO3-, etc.)
redox (oxidation-reduction) reaction
a reaction where electrons are transferred between 2 substances (electrons tracked using oxidation numbers)