reactants
starting chemicals in a chemical equation; left of arrow
products
ending chemicals in a chemical reaction; right of arrow
law of conservation of mass
matter is neither created nor destroyed; the form of matter may change but the total amount of matter stays constant; mass of reactant = mass of products
balanced equation
a chemical equation in which there are equal numbers of each type of atom on each side of the equation
coefficient
a number placed in front of a compound in an equation that indicates the number of atoms/molecules/formula units involved in a chemical reaction
synthesis
reactants combine to produce one compound; one product
decomposition
a reactant breaks down into two or more components; one reactant
single replacement
a single element takes the place of another element in a compound; an element and a compound produce a different element and compound
double replacement
elements in two compounds switch places; two compounds make two different compounds
Endothermic
a reaction that absorbs energy
Exothermic
a reaction in which energy is released
Activation energy
The minimum amount of energy needed to start a chemical reaction
Factors that control the rate of a reaction
temp, surface area, concentration, catalyst or inhibitors
Catalyst
Any substance that speeds up the rate of a reaction
Inhibitor
Any substance that slows down the rate of a reaction
Concentration
The amount of a substance in a given volume
Common ions
Sodium (Na+) Potassium (K+) Chlorid (Cl-) Calcium (Ca+) Iron (Fe+) Posphorous (P-)
Binary compound
composed of two elements first write the symbol of the cation and then the anion. Then add subscripts as needed to balance charges.
Mass ratio
Writing formulas
Naming compounds
Mole
representative particles of of a substance. SI unit for measuring the amount of a substance
Avogadro's number
Converting Number of Atoms to moles
Calculate number of moles to atoms
moles -> molecules -> atoms
Molar Mass
the mass of a mole of an element.
Mole to Mass
Determine the mass, in grams, of 9.45 moles of aluminum oxide (Al2O3).
Convert Mass to Moles
Calculate how many moles of iron(III) oxide are contained in 92.2 grams of pure Fe2O3.
Avogadro's Law
equal volumes of gases at a given temperature and pressure contain equal numbers of molecules.
Using Avogadro's Law
Determine the volume, in liters, of 0.60 moles SO2 gas at STP.
Molar Mass STP
The density of a gaseous compound containing carbon and oxygen is found to be 1.964 g/L at STP. What is the molar mass of the compound?
Percent Composition
the relative amounts of the elements in a compound. must add up to 100%.
Calculating Percent Composition
Percent Composition From a Formula
Calculate the percent composition of propane (C3H8).
Mass from Percent Composition
Calculate the mass of carbon and the mass of hydrogen in 82.0 grams of propane (C3H8).
Calculating Empirical Formula,
A compound is analyzed and found to contain 25.9% nitrogen and 74.1% oxygen. What is the empirical formula of the compound?
Molecular Formulas
shows the actual numbers of atoms in a molecule of the compound.
Calculating Molecular Formula
Calculate the molecular formula of a compound whose molar mass is 60.0 g/mol and empirical formula is CH4N.
Balancing a Chemical Equation
Determine the number of atoms of each element in the reactants and products. Count polyatomic ion as a single unit. If it is unchanged on both sides.
Begin by balancing elements that appear on both sides.
Do not change subscripts.
Polyatomic Ion
An ion made of two or more atoms
Combination Reaction
a chemical change in which two or more substances react to form a single new substance
Decomposition Reaction
a reaction in which a single compound breaks down to form two or more simpler substances
Single Replacement Reaction
a chemical change in which one element replaces a second element in a compound
Double Replacement Reaction
a chemical change that involves an exchange of positive ions between two compounds
Precipitate Reaction
Reaction that produces a precipitate
Combustion Reaction
occurs when a substance reacts with oxygen to produce energy in the form of heat and light
Chemical Reactivity
bleach
Sodium hypochlorite is the chemical name for
Ammonia
NH3
Baking soda
NaHCO3