chapter 10 test Flashcards
(16 cards)
how many particals is a mole
6.02e23
at stp, how many l is a mole
22.4 l
Mole
A mole is defined as 6.02214076 × 1023 of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance
avogadro’s number
The Avogadro number, sometimes denoted N or N₀, is the number of constituent particles that are contained in one mole, the international unit of amount of substance: by definition, exactly 6.02214076×10²³, and it is dimensionless. It is named after the scientist Amedeo Avogadro
representative particle
A representative particle is the smallest unit of a substance that can be broken down without altering the composition. Matter is composed of three types of representative particles: atoms, molecules and formula units.
The representative particle of an ionic compound
the formula unit.
the representative particle of molecular compounds. It is also the representative particle of diatomic elements
The molecule
molar mass
In chemistry, the molar mass of a chemical compound is defined as the mass of a sample of that compound divided by the amount of substance in that sample, measured in moles. The molar mass is a bulk, not molecular, property of a substance.
Avogadro’s hypothesis
a law stating that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.
STP
STP in chemistry is the abbreviation for Standard Temperature and Pressure. STP most commonly is used when performing calculations on gases, such as gas density.
standard temp and pressure is
The standard temperature is 273 K (0° Celsius or 32° Fahrenheit) and the standard pressure is 1 atm pressure
MOLAR VOLUME
The molar volume, symbol Vm, is the volume occupied by one mole of a substance (chemical element or chemical compound) at a given temperature and pressure. It is equal to the molar mass (M) divided by the mass density (ρ).
PERCENT COMPOSITION
Percent composition is the term used to describe the percent by mass of each element in a compound. It is typically found using the molar mass values for both the elements in the compound and the compound itself.
emperical formula
The empirical formula of a compound is the simplest whole number ratio of each type of atom in a compound. It can be the same as the compound’s molecular formula, but not always. An empirical formula can be calculated from information about the mass of each element in a compound or from the percentage composition.
MOLECULAR FORMULA
A molecular formula consists of the chemical symbols for the constituent elements followed by numeric subscripts describing the number of atoms of each element present in the molecule. The empirical formula represents the simplest whole-integer ratio of atoms in a compound.
Atomic mass
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
