Chapter 3 - Mass Relationships in Chemical Reactions

Chemists

________ use moles to quantify atoms and molecules.

gaseous atoms

By dislodging an electron from each atom or molecule, collisions between electrons and ________ produce positive ions.

quantitative analysis of reactants

The ________ and products in a chemical reaction is known as stoichiometry.

Chemists

________ have devised a standard way to depict chemical reactions using chemical equations to communicate with one another.

Atomic mass

mass of an atom in atomic mass units, according to international consensus (amu)

One atomic mass unit

defined as a mass that is one-twelfth that of a carbon-12 atom

Mole (mol)

amount of a substance in the SI system that has the same number of elementary entities as there are atoms in 12 g (or 0.012 kg) of carbon-12 isotope

Molecular mass (in AMU)

mass of one molecule

Stoichiometry

quantitative analysis of reactants and products in a chemical reaction

Excess reactants

present in greater quantities than are required to react with the limiting reagent

Theoretical yield

determined by the amount of limiting reactant present at the start of the reaction—that is, the amount of product that would result if all of the limiting reactants reacted

Actual yield

amount of product obtained from a reaction, is smaller than the theoretical yield

Percent yield

ratio of the actual yield to the expected yield, to measure how effective a reaction is