NMAT Chem

Density

Mass per unit volume

Specific gravity

Can be used to determine if object will sink or float

Intensive property

Properties that does not depend on the amount of matter in a substance; value doesn’t change no matter how many or few

Boiling point

Intensive property; temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and the liquid changes into a vapor

Extensive property

Properties that depend on the amount of matter in a substance

Chemical property

Properties that are determined without changing the identity of the substance; dependent on the composition

Solubility

Maximum amount of solute that can be dissolved in a particular solvent under specific conditions; often expressed as a ratio or other measures of concentration

Unsaturated

Contains less solute than the solvent is capable of dissolving under the given conditions; amount dissolved is less than maximum

Saturated

Contains the maximum quantity of solute that is normally possible at a given temperature; not all will be dissolved

Supersaturated

Contains more solute than normally expected for a saturated solution; amount of solute is more than maximum; can only be achieved if you alter or lower the solubility

Molarity

Protons

Positively charged sub-atomic particle with a mass of 1.67×10-27 kg

Neutrons

Neutral charge and has a mass of 1.67×10-27 kg

Electrons

Negatively charged particles with a mass of 9.11×10-31 kg that is considered to be negligible; not in nucleus; lightest mass

Atomic number

Equal to the number of protons

Mass number

Equal to the sum of the number of protons and neutrons

Charge

Equal to the difference between number of protons and the number of electrons

Atomic weight

Weighted average of the mass numbers of the isotopes of that particular element

Isotopes

Atoms of the same element but have the same number of protons but different number of neutrons, thus different mass number

Isotones

Elements with the same number of neutrons

Isobars

Atomic species having the same mass number but different atomic number

Isoelectronic

Elements having the same number of electrons

Metals

Gives electrons; highly conductive for heat and electricity

Nonmetals

Receives electrons; poor conductors; high electronegativities and ionization energies

Aufbau principle

Electrons occupy lowest energy orbitals and builds up

Hund’s rule

Electrons occupy empty orbitals before doubling

Ionic bonds

Transfer of electrons

Covalent bonds

Sharing of electrons

Dipole-dipole & Hydrogen bonding

Strongest electrostatic interactions

Ideal gas equation

Synthesis

Two or more elements or compounds combine to make a more complex substance

Decomposition

Compounds break down into simpler substances

Single replacement

Occurs when one element replaces another in a compound

Double replacement

Occurs when different atoms in two different compounds trade places

Oxidation

Loss of electrons

Reduction

Gain of electrons

Limiting reagent

Reactant that is first to be totally consumed halting further reactions

Excess reagent

Reactant that is left when the limiting reagent is consumed

Enthalpy

Total energy of an object or system

Endothermic

Reactions require addition of energy; product has higher enthalpy than reactant

Exothermic

Reactions require removal of energy; product has a lower enthalpy than reactant

Spontaneous reactions

Reactions that require a very small activation energy and can start without external interference

Le chatelier’s principle

When an equilibrium system is subjected to a change in temperature, pressure, or concentration of a reacting species, the system responds by attaining a new equilibrium that partially offsets the impact of the change

Arrhenius acid

H+ producer

Arrhenius base

OH- producer

Brønsted-lowry acid

H+ donor

Brønsted-lowry base

H+ acceptor

Lewis acid

Electron-pair acceptor

Lewis base

Electron-pair donor

Acids

Sour in taste; corrosive to most metals

Bases

Bitter in taste; slippery to the touch

Titrant

Substance with known concentration to be added

Analyte

Substance whose unknown concentration is to be determined

Indicator

Substance that changes property under certain conditions to signal when to stop adding the titrant

Equivalence point

Added titrant neutralizes the analyte

End point

Point when the pH changes the color of the indicator