Chapter 2: Calculations Used in Analytical Chemistry Flashcards
is a non-SI unit of length that is widely used to express the wavelength of very short radiation such as X-rays
Angstrom
What does SI stand for
International System of Units
SI is the initialism for the French acronym, which stands for
Systeme International d’Unites
Four of the seven SI base units, kg, ampere, kelvin, and mole were redefined by setting exact values for
Planck’s constant
elementary electric charge
boltzmann’s constnt
avogadro’s constant
is an unchanging measure of the quantity of matter in an object.
Mass
is the force of attraction between an object and its surroundings, principally Earth
Weight
is used to compare the mass of an object with the mass of one or more standard masses.
balance
process of comparing masses is usually called
weighing
the objects of known mass as well as the results of weighing are frequently called
weights
we use ______ for the act of determining the mass of an object
Balance
We often say _________ to mean the standard masses used in weighing.
weights
is the SI unit for the amount of a chemical substance
mole (abbreviated mol)
one mole contains
6.022x10^23 elementary entities (molecules, particles, ions, atoms, electrons, etc.)
It is the substance’s mass in grams of 1 mole of that substance
molar mass
is 1/1000 of a mole
millimole
mass in grams of a millimole, is likewise 1/1000 of the molar mass is called
millimolar mass
other terms of dimensional analysis
factor-label method
picket fence method
of a solution of a solute species X is the number of moles of that species that is contained in 1 L of the solution (not 1 L of the solvent).
molar concentration Cx
is the molar concentration of a
particular species in a solution.
Molar equilibrium concentration
is a convenient way to express concentration
parts per million
formula of ppm
mass of solute/ mass of solution x 10^6 ppm
formula of weight percent
weight of solute/ weight of solution x 100
formula of volume percent
volume solute/ volume of solution x 100
formula of weight/volume percent
weight solute/ volume of solx 100
formula for ppb
mass of solute/mass of solutionx 10^9
mg/L
The _________ of a substance is its mass per unit volume,
density
is the ratio of its mass to the mass of an equal volume of water at 4°C.
specific gravity
expresses the mass of a
substance per unit volume. In SI
units, density is expressed in units of
kg/L or alternatively g/mL.
density
is the ratio of the
mass of a substance to the mass of an
equal volume of water.
specific gravity
gives the simplest whole-number ratio of atoms in a chemical compound
empirical formula
specifies the number of atoms in a molecule.
molecular formula
The ___________ of a reaction
is the relationship among the
number of moles of reactants
and products as represented by a
balanced chemical equation.
stoichiometry
