89 Cards in this Set
| Front | Back |
|---|---|
|
Pressure
|
The force exerted per unit area of surface
|
|
Acceleration
|
The change of speed per unit time. m/s
|
|
Force
|
Mass x constant acceleration of gravity
|
|
Pressure
|
Force/area
|
|
Barometer
|
Device for measuring the pressure of the atmosphere
|
|
Manometer
|
Device that measures the pressure of a gas or liquid in a vessel
|
|
Millimeters of mercury
|
Aka torr. A unit of pressure equal to that exerted by a column of mercury m high at 0.00 degrees Celsius
|
|
Atmosphere
|
Unit of pressure equal to exactly 760 mmHg
|
|
P=gdh
|
Relationship between pressure and the height of a liquid column in a barometer or manometer
|
|
Boyle's Law
|
The volume of a sample of gas at a given temperature varies inversely with the applied pressure
|
|
Equation for Boyle's law
|
PV=constant
|
|
John Dalton & Joseph Louis Gay-Lussac theory
|
A sample of gas at a fixed pressure increases in volume linearly with temperature
|
|
Charles Law
|
The volume occupied by any sample of gas at a constant pressure is directly proportional to the absolute temperature
|
|
Equation for Charles Law
|
V/T
|
|
Combined Gas law
|
The volume occupied by a given amount of gas is proportional to the absolute temperature divided by the pressure.
|
|
Avogadro's Law
|
Equal volume of any two gases at the same temperature and pressure contain the same number of molecules
|
|
Molar gas volume
|
Vm. The volume of one mole of gas
|
|
Standard temperature and pressure
|
Reference conditions for gases chosen by convention to be 0 degrees Celsius and pressure
|
|
Avogadro's law on molar gas volume
|
The molar gas volume at a given temp and pressure is a specific constant independent of the nature of the gas
|
|
Ideal gas equation
|
V= constant x T/P
|
|
Molar gas constant
|
R. The constant of proportionality relating the molar volume of a gas to temp and pressure
|
|
Ideal gas law
|
Combination of the gas laws. Includes all the information contained in Boyle's, Charles's, and Avogadro's laws
|
|
According to John Dalton
|
Each gas in a mixture of unreactive gases act as though it were the only gas in the mixture.
|
|
Ideal gas law equation
|
PV=nRT
|
|
Partial pressure
|
The pressure exerted by a particular gas in a mixture
|
|
Dalton's law of partial pressure
|
The sum of the partial pressures of all the different gasses in a mixture is equal to the total pressure of the mixture
|
|
Mole fraction
|
A component gas is the fraction of moles of that component in the total miles of gas mixtures.
|
|
Kinetic-Molecular theory
|
A gas consists of molecules in constant rands motion
|
|
Postulates
|
The basic statements from which all conclusions of predictions of a theory are deduced
|
|
Kinetic postulate 1
|
Gases are composed of molecules whose size is negligible compared with the average distance between them
|
|
Kinetic postulate 2
|
Molecules move randomly in straight lines in all directions and at various speeds
|
|
Kinetic postulate 3
|
The forces of attraction or repulsion between two molecules in a gas are very weak or negligible, expect when they collide
|
|
Kinetic postulate 4
|
When molecules collide with one another, the collisions are elastic
|
|
Elastic collision
|
The total kinetic energy remains constant; no kinetic energy is lost
|
|
Kinetic Postulate 5
|
The average kinetic energy of a molecule is proportional to the absolute temperature
|
|
According to the kinetic theory
|
The pressure of a gas results from the bombardment of container walls by molecules
|
|
According to the kinetic theory
|
Pressure of gas will be proportional to the frequency of molecular collisions with a surface and to the average force exerted by a molecule in collision
|
|
Speeds of molecules Ina gas vary over a range of values
|
Speeds of molecules Ina gas vary over a range of values
|
|
Root-mean- square molecular speed
|
A type of average molecular speed, equal to the speed of a molecule having the average molecular kinetic energy
|
|
Gaseous diffusion
|
The precedes where by a gas spreads out through another gas to occupy the space uniformly.
|
|
Effusion
|
Process in which a gas flows through a small hole in a container
|
|
Graham's law of effusion
|
The rate of effusion of gas molecules from a particular hole is inversely proportional to the square root of the molecular mass of the gas at constant temperature and pressure
|
|
Rate of effusion depend on 3 factors
|
1. The cross-sectional area of the hole- larger the hole, more likely molecules are to escape
2. The number of molecules per unit volume- more crowded, more likely to encounter the hole
3. The average molecular speed- faster the molecules, the sooner they will escape
|
|
Van set Waals equation
|
An equation similar to the ideal gas law, but included two constants, a and b, to account for deviations from ideal behavior.
(P+ n2a/V2) (V-nb)= nRT
|
|
Chemical bond
|
A strong attractive force that exists between certain atoms in a substance
|
|
Covalent bonding
|
Two atoms share valence electrons, which are attracted to the positively charged cored of both atoms, thus linking them
|
|
Metallic bonding
|
Valence electrons move throughout the crystal. Attraction holds the crystal together
|
|
Ionic bond
|
A chemical bond formed by the electrostatic attraction between positive and negative ions.
|
|
Cation
|
Atom that loses electrons. Positive
|
|
Anion
|
Atom that gains electrons. Negative
|
|
Lewis electron- for symbol
|
A symbol in which the electrons in the valence she'll of an atom of ion are represented by dots places around the letter symbol of the element
|
|
Ionic bonding steps
|
1. an electron is transferred between the the two separate atoms to give ions
2. The ions then attract one another to form an ionic bond
|
|
Coulomb's law
|
Potential energy obtained in bringing two charges, Q1 and Q2, initially far apart, up to a distance(r) apart is directly proportional to the product of the charges and inversely proportional to the distance between them.
E= (kQ1Q2)/ r
|
|
Lattice energy
|
The change in energy that occurs when an ionic solid is separated into isolated ions in the gas phase
|
|
Ionic bonding occurs
|
Between a reactive metal and a reactive nonmetal
|
|
Ionic substances are
|
High melting solids
|
|
Cations of group IA to IIIA having noble gas or pseudo noble gas configurations
|
The ion charges equal the group numbers
|
|
Cations of groups IIIA to VA having noble gas or pseudo noble gas configurations
|
The ion charges equal the group numbers minus two
|
|
Anions of groups VA to VIIA having noble gas or pseudo noble gas configurations
|
The ion charges equal the group numbers minus eight
|
|
Ionic radius
|
A measure of the size of the spherical region around the nucleus of an ion within which the electrons are most likely to be found.
|
|
Isoelectronic
|
Refers to different species having the same number and configuration of electrons
|
|
Lewis electron dot formula
|
Formula using dogs to represent valence electrons
|
|
Bonding pair
|
An electron pair shared between two atoms
|
|
Lone, or nonbonding, pair
|
An electron pair that remains on one atom and is not shared
|
|
Coordinate covalent bond
|
A bond formed when both electrons of the bond are donated by one atom
|
|
Octet rule
|
The tendency of atoms in molecules to have eight electrons in their valence shells
|
|
Single bond
|
A covalent bond in which a single pair of electrons is shared by two atoms
|
|
Double bond
|
A covalent bond in which two pairs of electrons are shared by two atoms
|
|
Triple bond
|
A cone lent bond in which three pairs of electrons are shared by two electrons
|
|
Polar covalent bond
|
A covalent bond in which the bonding electrons spend more time best one atom than the other
|
|
Electronegativity
|
A measure of the ability of an atom in a molecule to draw bonding electrons to itself l
|
|
Large electronegativity
|
An atom that tends to pick up electrons easily and hold on to them strongly
|
|
Small electronegativity
|
An atom that tends to lose electrons readily and has little tendency to gain electrons
|
|
Metals
|
...
|
|
Nonmetals
|
Most electronegative
|
|
Nonpolar
|
Small electronegativity
|
|
Polar
|
Large electronegativity
|
|
Delocalized bonding
|
Type of bonding in which a bonding pair of electrons is spread over a number of atoms rather than localized between two
|
|
Resonance description
|
Describe the electron structure of a molecule having delocalized bonding by writing all possible electron dot formulas
|
|
Exceptions to the octet rule
|
1. A group of molecules with an atom having fewer than eight valence electrons around it
2. A group of molecules with an atom having more than eight valence electrons around it
|
|
Formal charge
|
Hypothetical charge you obtain by assuming that bonding electrons are equally shared between the bonded atoms and that the electrons of each line pair belong completely to one atom.
|
|
Rules for formal charge
|
1. 1/2 of the electrons of a bond are assigned to each atom in the bond
2. Both electrons of a line pair are assigned to the atom to which the lone pair belongs
|
|
Rules for deciding which of several resonance formulas best approximates the electron distribution of a molecule or ion
|
Rule A: whenever you can write several Lewis formulas for a molecule, choose the one having the lowest magnitudes of formal charges
Rule B: when two proposed Lewis formulas for a molecule have the same magnitudes of formal charges, choose the one having the negative formal charge in the…
|
|
Bond length
|
The distance between the nuclei in a bond.
|
|
Covalent radius
|
The value for the atom in a set of covalent radio assigned to atoms in such a way that the sum of the covalent radio of atoms A and B predicts the approximate A-B bond length
|
|
Bond order
|
The number of pairs of electrons in a bond
|
|
Bond dissociation
|
The energy required to break a particular bond in a molecule
|
|
Bond enthalpy
|
Can use as a measure of the average strength of a bond in its compound. The average enthalpy change for the breaking of an A-B bond in a molecule in the gas phase
|
|
Molecular geometry
|
The general shape of a molecule, as determined by the relative positions of the atomic nuclei
|
CHEM 115: EXAM 2