Ch 5: Solutions + Ch 6: Gases + Ch. 7 Liquids and Solids Flashcards
Units for pressure = ?
1 atm = 760 torr = 760 mmHg
Gases behave more ideally under ___ pressure and ____ temperature
low pressure
high temperature
(this is stated by the ideal gas theory an kinetic molecular theory)
- at higher temperature collisions are more elastic and there will be no attraction among molecules
What does the kinetic molecular theory state?
- gas molecule do not have volume
- there are no attraction forces between molecules
- collisions are elastic = no intermolecular forces = no loss of energy
- average kinetic energy depends on temperature
What is the R gas constant?
8.3145 J/mol K
What is avogadro’s law?
volume is proportional to moles
Boyle’s law?
pressure is inversely proportional to volume
Charles’ law?
volume is proportional to temperature
Dalton’s law of partial pressure?
mix of gases, total pressure of mixture = summation of partial pressure of individual gases (molar fraction of gas times total pressure)
Graham’s Law of Effusion
rate of effusion of a gas inversely proportional to square root of it’s molar mass
___ bond are between tightly packed metal ions and a pool of electrons
metallic
What forces hold liquids together?
intermolecular forces:
- van der waals
- dipole-dipole/polar
- hydrogen bonding
A substance at very high temperature and pressure is at it’s
critical point.
= supercritical fluid with gaseous and liquid properties
What is the freezing point depression formula?
dT freezing = i Kfreezing M
M = mol solute / mass of solvent
If a type of solute is not important bt the van’t Hoff factor is important, what type of property is this?
colligative
When two substances with different vapor pressures are combined, vapor pressure of mixture changes is according to who’s law?
Raoult’s law
P total = Pa + Pb
Lower vapor pressure when adding salt in comparison to water.
Lower vapor pressure means fewer liquid particles vaporized.
This yields…
boiling point elevation
dt = iKboilingM
What is sensible heat?
energy required to increase the temperature of a substance
Rate of dissolution = rate of precipitation at…
molar solubility
solid form precipitated and dissolved form are at equilibrium
For solids in liquids:
incr temperature means _____ solubility
increase solubility
For gases in liquids:
incr temperature means ______ solubility
decrease solubility
For gases in liquids:
increase pressure means ____
increase solubility
Soluble or insoluble: CsOH
soluble
group 2 salts are always soluble
Soluble or insoluble:
NH3NO2
soluble
nitrate, perchlorate, acetate are always soluble (think nitrate dissolving in nitrogen cycle
Soluble or insoluble:
AgClO4
soluble
silver, lead, mercury is insoluble except with nitrates, perchlorates, acetates
High vapor pressure means ____ intermolecular forces
weaker
therefore, substances will more easily evaporate
= more volatile
What are the four properties of colligative properties?
- Vapour pressure depression
- Boiling Point elevation
- Freezing point depression
- Osmotic Pressure
What is the difference between dissolution and solvation?
dissolution: solvent-solvent and solute-solute intermolecular attractions that need to be broken
solvation: solvent-solute intermolecular attractions that need to be formed to form a soluution
What is stronger hydrogen bond or ion-dipole?
ion-dipole
-note hydrogen bond is a very strong type of dipole-dipole
Intermolecular forces play a role in boiling points how so?
stronger intermolecular forces that hold molecules together, more energy required to separate i.e. boiling point is higher
How do intermolecular forces play a role in determining solubility?
solute must be surrounded by solvent (solvated)
solute-solvent bonds stronger than > solute-solute or solvent-solvent bonds
Boiling point: True or false
weaker intermolecular forces will have higher boiling point
False
stronger force = higher bp
need more energy to break strong force
Boiling point: True or false
between nonpolar molecules the one with more extended molecule will have higher boiling point
True
as length of hydrocarbonds increase, boiling point and melting point increases
Boiling point:
Do smaller or larger molecules have higher boiling points?
larger = higher bp
