Exam One Flashcards
As the molecules of a gas attract each other into a liquid and then become fixed in a solid, the system is […] energy. This is an […] change.
loses; exothermic
Overcome the attractive forces that keep the particles fixed in place in a solid or near each other in a liquid. The system must […] energy. This is an […] change.
absorbs; endothermic
Melting or […]. The enthalpy change is […]. For freezing the enthalpy change is […].
fusion; positive; negative
Gas formation or […]. The enthalpy change is […]. For condensation, the enthalpy change is […].
vaporization; positive; negative
Sublimation:
solid goes to a gas
Sublimation calculation of enthalpy change:
heats of fusion + heats of vaporization
Deposition:
gas goes to solid
Deposition calculation of enthalpy change:
(-) heats of fusion + (-) heats of vaporization
Molecules with weaker IMF are held […] tightly at the surface and vaporize more […]. Weaker IMFs are, the […] the vapor pressure.
less; easily; higher
Vapor pressure and temperature can be converted to a linear relationship with the use of…
Clausius-Clapeyron
Clausius-Clapeyron Equation at one at two known temperatures:
lnP = (-Hvap/R) (1/T) + C
ln(P2/P1) = (-Hvap/R) (1/T2-1/T1)
R = 8.314 J/mol*K
% By Mass Equation:
mass of solute/ mass of solution
% By Volume Equation:
volume of solute/ volume of solution
Molality Equation:
amount of solute/ mass of solvent (kg)
Molarity Equation:
amount of solute/ volume of solution
Mole Fraction:
amount (mole of solute)/ amount of solution (mole solute + mole of solvent)
Regions of the phase diagram represent…
conditions of pressure and temperature at which the phase is stable
Solid-liquid line has a slightly positive slope because…
the solid is more dense than the liquid (except water)
The triple pint of a phase diagram where…
all three phases are in equilibrium (simultaneous work)
Critical point:
two densities become equal and the phase boundary disappears
How does the phase diagram for water differ?
the solid-liquid line has a negative slop because the solid form is less dense
How does the phase diagram for water differ?
the solid-liquid line has a negative slop because the solid form is less dense
List the 3 bonding forces:
ionic
covalent
metallic
List the 6 IMF forces:
ion-dipole (NaH2O)
H-bond (H to N, O, F)
ion-induced dipole (FeO2)
dipole-dipole (ICl-ICl)
dipole-induced dipole (HCl-ClCl)
dispersion (F2-F2)
Ion-Dipole forces: The prime example would be…
Why does this occur?
any ionic compound dissolving in water
the attraction between the negative pole and ion is greater than the between the ions themselves
If the dipole-dipole forces of 2 compounds have a similar mass, what can determine the stronger force?
the one with the greater dipole moment
For a NP molecule, distortion of an electron cloud induces a […].
temporary dipole moment
For a P molecule, distortion of an electron cloud induces an […].
increase in the already existing dipole moment
Polarizability:
how easily the electron cloud of an atom can be distorted
Which is more polarizable: smaller particles or larger ones?
larger; smaller molecules are held more closely to the nucleus