IB Chemistry Chapter 3 Terms

Chemical Stoichiometry
the calculation of the quantities of material consumed and produced in chemical reactions
Mass Spectrometer
an instrument used to determine the relative masses of atoms by the deflection of their ions on a magnetic field
Average Atomic Mass
a value reflecting the average mass of the naturally occurring isotopes composing the element
the number equal to the number of carbon atoms in exactly 12 grams of pure ^12C; Avogadro’s number. One mole represents 6.022 x 10^23 units.
Avogadro’s Number
the number of atoms in exactly 12 grams of pure ^12C, equal to 6.022 x 10^23
Molar Mass
the mass in grams of one mole of molecules or formula units of a substance; also called molecular weight
Mass Percent
the percent by mass of a component of a mixture or a given element in a compound
Empirical Formula
the simplest whole number ratio of atoms in a compound
Molecular Formula
the exact formula of a molecule, giving the types of atoms and number of each type
Chemical Equation
a representation of a chemical reaction showing the relative numbers of reactant and product molecules
a starting substance in a chemical reaction; it appears to the left of the arrow in a chemical equation
a substance resulting from a chemical reaction. It is shown to the right of the arrow in a chemical equation.
Balancing a Chemical Equation
the same number of each type of atom must be present in the product and reactant sides of the equation
Mole Ratio
the ratio of moles of one substance to moles of another substance in a balanced chemical equation
Stoichiometric Quantities
quantities of reactants mixed in exactly the correct amounts so that all are used up at the same time
Haber Process
the manufacture of ammonia from nitrogen and hydrogen, carried out at high pressure and high temperature with the aid of a catalyst
Limiting Reactant (Reagent)
the reactant that is completely consumed when a reaction is run to completion
Theoretical Yield
the maximum amount of a given product that can be formed when the limiting reactant is completely consumed
Percent Yield
the actual yield of a product as a percentage of the theoretical yield