Class 3 Flashcards
What is the relative IMF for solids, liquids, gases, and ideal gases?
Solid > Liquid > Gas > Ideal gas
One of the premises of ideal gases is that intermolecular forces are very minimal.
What is more likely to be solid: polar or nonpolar? Why?
Polar because it has more IMF, particles hold together more tightly
What is the phase transition from gas to solid called?
Deposition
Endothermic reactions are always associated with what?
Breaking bonds
What is the equation for heat energy to warm a substance?
q = mc(delta)T
where m = mass (kg)
c = specific heat (J/gK)
What is heat capacity (C)?
C (heat capacity) = mc
where c is the specific heat
What is the specific heat of water?
4.18 J/gK
What is the critical point?
The T/P at which the difference between liquid phase and gas phase is no longer distinct.
What is the triple point?
The T/P at which the solid, liquid, and gas phases of a substance can coexist.
What is unique about the phase diagram for water?
The solid/liquid boundary line angles LEFT because as pressure increases, the water mp decreases. This is called the “ice skating effect” like when the pressure from an ice skate melts the water.
IMF is ________ proportional to V
Indirectly. High IMF is indicative of tightly bound bonds and thus a solid, smaller form.
IMF is ________ proportional to P
Indirectly
P being the force exerted by gas particles on the surface.
Increasing pressure on a substance will cause density to _______.
Increase
IMF is _______ proportional to density
directly
What is vapor pressure?
The force exerted by the gas particles that vaporize from a solid or liquid sample.
Does external pressure have an effect on vapor pressure?
NO NO NO! Air pressure DOES NOT MATTER!
External pressure is ______ proportional to vapor pressure.
Directly
IMF is __________ proportional to vapor pressure.
Indirectly
What is boiling point?
When vapor pressure is equal to atmospheric pressure, causing liquid to turn to gas.
IMF is _______ proportional to boiling point.
Directly
What is the “super” hydrogen bonder (and thus has a very high IMF)?
Water! H2O
Is HF a weak acid?
Yes
Is solvation an exothermic process?
Yes
What is solubility?
The amount of a substance that can dissolve in a specific solvent at a specific temperature.
Solubility of gas in water is _________ proportional to temperature.
Indirectly
Solubility of gas in water is __________ proportional to pressure.
Directly
What are some ions that are ALWAYS soluble in water?
H+, NH4+, NO3-, CH3COO-, ClO4-
What are some ions that are usually INSOLUBLE in water?
Ag+, PB2+, Pb4+, Hg22+, Hg2+, CO32-, PO43-, S2-2
Describe the IMF and travel behavior of ideal gases?
ZERO IMF, travels in straight lines
Small particle size so minimal collisions
Kinetic energy is proportional to temperature
When is ideality favored?
High temp, low pressure because collisions are minimized
1 atm is equal to how many Pa, mmHg, and torr?
1 atm = 100,000 Pa, 760 mmHg, 760 torr
What is Boyle’s Law?
Pressure and volume are inversely proportional
Temperature is _________ proportional to volume.
Directly
What is Charles’ Law?
Temperature and volume are directly proportional
Temperature is _____ proportional to pressure
Directly
What is the combined gas law?
P1V1/T1 = P2V2/T2
What is Avogadro’s Law?
The volume of a sample of gas is proportional to the number of gas particles in the container
What is the ideal gas law constant (R)
R = 0.08 Latm/molK
What is the volume of of 1 mole of gas at STP?
22.4 L
How does the pressure in a container change for real gases versus ideal? How is it corrected for?
Real gases will have a slightly lower pressure than ideal do to non-straight collision paths in reality.
P = nRT/(v-nb) - n^2/v^2a
a = arbitrary value of attraction
Does ideal gas have a greater volume than the real gas? How is it corrected for?
Yes because the real gas actually takes up some space in the box.
v-nb is the correction factor
What is Dalton’s law?
The partial pressure of a gas in a mixture is proportional to its mole fraction.
The rate of diffusion (v) of a gas is _______ proportional to its molecular weight (mw).
inversely
What is Graham’s law?
The rate of diffusion (v) of a gas is inversely proportional to its molecular weight (mw).
Heavy particles move slowly
Light particles move quickly
