Chemistry exam vocab
Terms
undefined, object
copy deck
- the capacity for doing work or supplying heat
- energy
- enery that transfers from one object to another because of temperature difference between them
- heat
- defined as the quantity of heat needed to raise the temperature of one gram of pure water one degree Celcius
- calorie
- the SI unit of energy
- joule
- 4.18 J
- 1 cal
- the quatntity of heat required to change an objects temperature by exactly one degree Celsius
- heat capacity
- amount of heat it take to raise one gram of a substance one degree Celsius
- specific heat capacity
- a heat absorbic process
- endothermic process
- a heat dissipating process
- exothermic process
- the measurement of heat changes for physical and chemical processes
- calorimetry
- the tendency of molecules and ions to move toward areas of lower concentration until the concentration is uniform thoughout the system
- diffusion
- the pressure exerted by each gas in a gaseous mixture
- partial pressure
- factors of gases
-
Pressure (kPa, atm, mm Hg)
Temperature (K)
Volume (L, mL) -
pressure and volume are inversely proportional in a gas, if temperature is kept constant
P1 x V1 = P2 x V2 - Boyle's Law
-
temperature and volume are directly proportional, if pressure is kept constant
V1/T1 = V2/T2 - Charles' Law
- (P1 x V1)/T1 = (P2 x V2)/T2
- Combined Gas Law
-
PV = nRT
(pressure x volume = # of moles x constant x temperature) - Ideal Gas Law
-
at a constant temperature and volume, total pressure exerted by a mix of gases is equal to the sum of partial pressures of the component gases
P1 + P2 + P3...= PT - Dalton's Law of Partial Pressure
- equal volume of gases at the same temperature pressure contain equal numbers of particles
- Avogadro's hypothesis
- rate of effusion of gas is inversely proportional to the square root of its molar mass
- Graham's Law
- STP
-
Standard Temperature and Pressure
T= 0 degrees C
P= 101.3 kPa, 760 mm Hg, 1 atm
V= 22.4 L - 1 nutritional Calorie
- 1000 calories
- the height of a wave
- amplitude
-
the pattern of frequencies obtained by passing light emited by atoms of an element in the gaseous state thorough a prism
the emission spectrum of each element is unique to that element - atomic emission spectrum
- the arrangement of electrons around the nucleous of an atom in its ground state
- electron configuration
- a region around the nucleous of an atom where an electron is likely to be moving
- energy level
-
a series of energy waves that travel in a vacuum at 3.0 10^10 cm/s
includes radio waves, microwaves, visible light, infrared and ultraviolet light, x-rays, and gamma rays - electromagnetic radiation
- the lowest energy level occupied by an electron when an atom is in its most stable energy state
- ground state
- (v) the number of wave cycles that pass a given point per unit of time
- frequency
- the distance between two adjacent crests of a wave
- wavelength
- the SI unit of frequency, equal to one cycle per second
- hertz
- electrons are ejected by certain metals when they absorb light with a frequency above a threshold frequency
- photoelectric effect
-
a quantum of light
a discrete bundle of electromagnetic energy that behaves as a particle - photon
- the amount of energy needed to move an electron
- quantum
- half the distance between the nuclei in a molecule consisting of identical...
- atomic radius
- the tendency for an atom to attract electrons to itself when it is chemically combined with another element
- electronegativity
- the energy required to remove an electron from a gaseous atom
- ionization energy
-
a vertical column of elements in the periodic table
the contituent elements of a group have similar chemical and physical properties - group
- a horizontal row of elements in the periodic table
- period
-
electrons enter orbitals of lowest energy first
lowest to highest - Aufbau principle
-
wave mechanics
wave like motions - de Broglie's equations
- cannot know both velocity and position of particle (electron) at the same time
- Heisenberg uncertainty principle
- each orbital will get one electron before any orbital gets two
- Hund's rule
-
two elecrons per orbital
now two electrons will have the same quantum number (NLMS) - Pauli exclusion principle
-
arranged by increasing atomic number
periodic repitition of physical and chemical properties - Periodic Law
- Group IA
- alkaline metals
- Group IIA
- alkaline earth metals
- Group VIIA
- halogens
- Group VIIIA
- noble gases
- A Group
- representative
- B Group
- transistion metals
- lanthanide and actinide series
-
rare earth metals
(inner transition) - two different atoms joined by a convalent bond and the bonding electrons are shared unequally
- polar
- atoms in molecules are alike and bonding electrons are shared equally
- nonpolar
- angle at which adjacent atoms in a molecule are attracted
- bond angle
-
a notation that depicts valence electrons as dots around the atomic structure of the element
the symbol represents inner electrons and atomic nucleus - electron dot structure
- a process by which several atomic orbitals (such as s and p)mix to form the same number of equivalent hybrid orbitals
- hybridization
- atoms react by gaining or losing electrons as to acquire the stable electron structure of a noble gas, usually eight valence elctrons
- octet rule
- any atom or group of atoms with a negative charge
- anion
- any atom or group of atoms with a positive charge
- cation
- a molecule in which one or more atoms is slightly negative and one or more is slightly positive, unless molecular geometry causes the polarities to cancel each other out
- polar molecule
-
a chemical formula that shows the arrangement of atoms in a molecule or polyatomic ion
each dash between two atoms indicates a pair of shared electrons - structural formula
- a pair of valence electrons that is not involved in bonding
- unshared pair
- an electron in the highest occupied energy level of an atom
- valence electrons
-
valence-shell electron-pair repulsion theory
because electron pairs repel, molecules adjust their shapes so that vealence-electron pairs are as far apart as possible - VSEPR theory
-
a term used to describe the weakest intermolecular attractions
these include dispersion forces and dipole interactions - van der Waals forces
-
the weakest kind of intermolecular attractions
this attraction is thought to be caused by the motion of electrons - dispersion force
- a relatively strong intermolecular force in which a hydrogen atom that is covalently bonded to a very electronegative atom is also weakly bonded to an unshared electron pair of another electronegative atom in the same moleculr or one nearby
- hydrogen bond
-
metal (cation) and nonmetal (anion) are bonded together
electrostatic attraction - ionic
-
two nonmetals are bonded together
share electrons - covalent
-
within metals
conducts electricity - metallic
-
an inward force that tends to minimize the surface area of a liquid
it causes the surface to behave as if it were a thin skin - surface tension
-
a suface active reagent
any sustance with molecules that interfere with the hydrogen bonding between water molecules, reducing surface tension
i.e. soaps and detergents - surfactants
- (aq) a solution in which the solvent is water
- aqueous solutions
- the dissolving medium in a solution
- solvent
- dissolved particles in a solution
- solute
-
a compound that conducts an electric current in aqueous solution or in the molten state
all ionic compounds are this - electrolyte
- a compound that does not conduct an electric current in aqueous solution or in the molten state
- nonelectrolyte
- a mixture form which some of the particles settle out slowly upon standing
- suspension
- a mixture whose particles are intermediate in size between those of a susupension and a solute solution
- colloid
- scattering of light by particles in a colloid or suspension, which causes a beam of light to become visible
- Tyndall effect
- the chaotic movement of colloidal paricles caused by collision with particles of the solvent in which they are dispersed
- Brownian motion
- the colloidal dispersion of one liquid in another
- emulsion
-
to lose water of hydration
the process occurs when the hydrate has a vapor pressure higher than that of water vapor in in the air - effloresce
- a term describing salts and other compounds that remove moisture form the air
- hygroscopic
- a hygroscopic substance used as a drying agent
- desiccant
-
a term describing a substance that removes sufficient water from the air to form a solution
the solution formed has a lower vapor pressure that that of the water in the air - deliquescent
-
a solution containing the maximum amount of solute for a given amount of solvent at a constant temperature and pressure
an equilibrium exists between undissolved solute and ions in solution - saturated solution
- a solution that contains less solute than a saturated solution at a given temperature and pressure
- unsaturated solution
- describes liquids that dissolve in each other
- miscible
- describes liquids that are insoluble in one another
- immiscible
- at a given temperature, the solubility of a gas in a liquid is directly porportional to the pressure of the gas above the liquid
- Henry's Law
-
a solution that contains more solute that it can theoretically hold and a given temperature
excess solute preciptates if a seed crystal is added - supersaturated solution
- (M) the concentration of solute in a solution expressed as the number of moles of solute dissolved in one liter of solution
- molarity
- bond angle of water
- 105 degrees
- at what temperature is water at maximum density
- 4 degrees C
- ? = moles of solute/liters of solution
- Molarity
- a compound that produces hydrogen ions in solution, is a hydrogen-ion donor, or an electron-pair acceptor
- acid
- a compound that produces hydroxide ions in solution, is a hydrogen-ion acceptor, or an electron-pair donor
- base
-
a solution in which the pH remains relatively constant when small amounts of acid of base are added
can be either a solution of a weak acid and the salt of a weak acid or a solution of a weak base and the salt of a weak base - buffer
-
a number used to denote the hydrogen-ion concentration, or acidity, of a solution
it is the negative logarithm of the hydrogen-ion concentration of a solution - pH
-
(H3O+) the positive ion formed when a woter molecule hains a hydrogen ion
all the hydrogen ion in aqueous solution are present as this - hydronim ion
- (OH-) the negative ion formed when a water molecule loses a hydrogen ion
- hydroxide ion
-
method used to determine the concentration of a solution (often an acid or base)
a solution of known concentration (the standard)is added to a measured amount of the solution of unknown concentration until an indicator signals the end point - titration
- an organic compound that contains only carbon and hydrogen
- hydrocarbon
- the controlled process by which hydrocarbons are broken down or rearranged into smaller, more useful molecules
- cracking
- a very large molecule formed by the covalent bonding of repeating small molecules, known as monomers
- polymers
- a simple molecule that repeatedly combines to form a polymer
- monomer
-
an organic compound having and -OH (hydroxyl)group
the general structure is R-OH - alocohol
-
an organic compound having amino (-NH2) and carboxylic (-COOH) groups in the same molecule
proteins are made from this - amino acid
-
a name originally given to the arenes because many of them have pleasant odors
any compound with bonding like that of benzene - aromatic compound
-
the name given to monomers and polymers of aldehydes and ketones that have numerous hydroxyl groups
i.e.sugars and starches - carbohydrates
- proteins that act as catalyst
- enzyme
-
a member of a large class of relatively water-insoluble organic compounds
i.e. fats, oils, waxes - lipids
-
a polymer of RNA or DNA found primarily in cell nuclei
play an important role in the transmission of hereditary characteristics, protein syntheis, and the control of cell activities - nucleic acid
-
one of the monomers that make up DNA and RNA
it consists of a nitrogen-containing base, a sugar, and a phosphate group - nucleotide
- any peptide with more than 100 amino acids
- protein
-
the process used to make soap
in involves the hydrolysis of fats or oils by a hot aqueous alikli-metal hydroxide - saponification
-
an organic compound in which all carbon atoms are joined by single covalent bonds
it contains the maximum number of hydrogen atoms - saturated compounds
- an organic compound with one or more double or triple carbon-carbon bonds
- unsaturated compounds
- functional group for organic acids
- COOH
- functional group for alcohols
- OH