Chem 103: Module 4
Avogadro's number - ANS6.022 x 10^23 atoms = 1 mole
1 u = ___ g - ANS1.661 x 10 ^-24 g
formula mass - ANSthe sum of the average atomic masses of each atom represented in the
chemical formula and is expressed in atomic mass units.
--The formula mass of a covalent compound is also called the molecular mass.
The chemical identity of a substance is defined by - ANSthe types and relative numbers of
atoms composing its fundamental entities (molecules in the case of covalent compounds, ions
in the case of ionic compounds).
A compound's percent composition provides - ANSthe mass percentage of each element in the
compound.
calculate the formula mass of a substance by - ANSsumming the average atomic masses of all
the atoms represented in the substance's formula.
A mole is defined as - ANSthe amount of substance containing the same number of discrete
entities (such as atoms, molecules, and ions) as the number of atoms in a sample of pure 12-C
weighing exactly 12 g
percent composition - ANSthe percentage by mass of each element in a compound
i.e. mass X / mass compound x 100%
stoichiometry - ANSrefers to the quantitative relationships between amounts of reactants and
products in a chemical reaction.
Combustion - ANSa reaction in which an element or compound burns in air or oxygen
--The combustion of compounds containing hydrogen and carbon (CxHy) will always produce
two products: water (H2O) and carbon dioxide (CO2).
--The same is true for the combustion of compounds containing hydrogen, carbon and oxygen
(CxHyOz)
Chemical formulas provide the - ANSidentities of the reactants and products involved in the
chemical change, allowing classification of the reaction
Coefficients provide the - ANSrelative numbers of these chemical species, allowing a
quantitative assessment of the relationships between the amounts of substances consumed and
produced by the reaction.
Avogadro's number - ANS6.022 x 10^23 atoms = 1 mole
1 u = ___ g - ANS1.661 x 10 ^-24 g
formula mass - ANSthe sum of the average atomic masses of each atom represented in the
chemical formula and is expressed in atomic mass units.
--The formula mass of a covalent compound is also called the molecular mass.
The chemical identity of a substance is defined by - ANSthe types and relative numbers of
atoms composing its fundamental entities (molecules in the case of covalent compounds, ions
in the case of ionic compounds).
A compound's percent composition provides - ANSthe mass percentage of each element in the
compound.
calculate the formula mass of a substance by - ANSsumming the average atomic masses of all
the atoms represented in the substance's formula.
A mole is defined as - ANSthe amount of substance containing the same number of discrete
entities (such as atoms, molecules, and ions) as the number of atoms in a sample of pure 12-C
weighing exactly 12 g
percent composition - ANSthe percentage by mass of each element in a compound
i.e. mass X / mass compound x 100%
stoichiometry - ANSrefers to the quantitative relationships between amounts of reactants and
products in a chemical reaction.
Combustion - ANSa reaction in which an element or compound burns in air or oxygen
--The combustion of compounds containing hydrogen and carbon (CxHy) will always produce
two products: water (H2O) and carbon dioxide (CO2).
--The same is true for the combustion of compounds containing hydrogen, carbon and oxygen
(CxHyOz)
Chemical formulas provide the - ANSidentities of the reactants and products involved in the
chemical change, allowing classification of the reaction
Coefficients provide the - ANSrelative numbers of these chemical species, allowing a
quantitative assessment of the relationships between the amounts of substances consumed and
produced by the reaction.
