GenChem8(Phases and Phase Changes) Flashcards
The degree to which two liquids can mix
Miscibility
Oil and water can’t mix because of repulsion due to polarity difference, they are
immiscible
Under extreme conditions two immiscible liquids can form a fairly homogeneous mixture called an
Emulsion
A solid, like NaCl that possesses an ordered structure. Its atoms exist in a specific three-dimensional geometric arrangement with repeating patters of atoms, ions, or molecules
Crystalline Solid
A solid that has no ordered three-dimensional arrangement, although the molecules are also fixed in space.
Amorphous Solid
Most solids are amorphous or crystalline?
Crystalline
What are the two most common forms of crystal solids?
Metal and ionic
Aggregates of positively and negatively charged ions; there are no discrete molecules.
Ionic Solids
What are the physical properties of ionic solids?
What accounts for these properties?
High MP and BP, low electrical conductivity in the solid phase
Strong electrostatic interactions.
These solids consist of metal atoms packed together as closely as possible.
Metallic Solids
What are the physical properties of metallic solids?
High melting and boiling point
The repeating units of crystals are represented by
Unit cells
This occurs when molecules near the surface of a liquid have enough kinetic energy to leave the liquid phase and escape into the gaseous phase.
What happens to the liquid each time it loses a high energy particle this way?
Evaporation (or vaporization)
The temperature decreases
The process where gas moves back into the liquid phase
Condensation
The pressure that the gas from a liquid exerts over the liquid is called the
Vapor Pressure
As temperature increases, vapor pressure….
The temperature at which the vapor pressure of the liquid equals the external pressure is called the
Increases
Boiling point
The transition from solid to liquid is…
Fusion or melting
The transition from liquid to solid is
Solidification, Crystallization, Freezing
The temperature at which fusion and crystallization occur can be called
Melting point OR freezing point, depending upon direction
These type of solids have a very sharp melting point
These type of solids have a broad range of melting temperatures
What accounts for this?
Crystal solids
Amorphous solids
How ordered their molecular distribution is
Physical properties derived solely from the number of particles present, not the nature of those particles. They are usually associated with dilute solutions.
Colligative properties
For every mole of solute particles dissolved in water, how much does the freezing point of water decrease?
1.86 °C
What is the freezing point of water?
The boiling point?
Freezing point = 0°C
Boiling point = 100°C
What is Chad’s formula for freezing point depression?
ΔT= -iKfm
A liquid boils when…
Vapor Pressure equals atmospheric pressure
What is Chad’s formula for boiling point elevation
ΔT= iKbm
If a 3m solution of something is added to water, how does that affect the ΔT=ikm equation?
You multiply K by three
What is the formula for osmotic pressure?
Π =MRT
M=molarity of the solutoin, R= ideal gas constant, T = temperature in Kelvins
Does osmotic pressure depend upon the identity of the solute?
No, just the amount of the solute. What it is is IRRELEVANT!
Mixtures of substances that combine to form a single phase, generally liquid.
Homogenous Solutions
Are NaCl, NH3, C12H22O11 solvents or solutes?
Are H20 and benzene solvents or solutes?
Solutes
Solvents
The interaction between solute and solvent molecules is known as…
Solvation or dissolution
When water is the solvent in dissolution (aka solvation) what is this process called?
What is the resulting solution called
Hydration
Aqueous Solution
Defined as the maximum amount of a substance that can be dissolved in a particular solvent at a particular temperature
Solubility
When the maximum amount of solute has been added to solvent that can be dissolved, the solution is said to be
A solution in which the proportion of solute to solvent is small is said to be…
A solution in which the proportion is large is
Saturated
Dilute
Concentrated
What are the two solubility rules that Chad mentioned in the videos?
- All group metals and NO3, NH3, CLO4, C2H3O2 salts are soluble
- Most Ag(+), Pb(2+), Hg2 (2+) are in insoluble in water. Exception: not when paired with group 1 metals
What is the exception to the second solubility rule?
Ag, Pb, and Hg are soluble when paired with group 1 metals
What does a roman numeral in front of an element indicate? Ex: Iron (II)
The positive charge of an ion of that element
Fe(2+)
When ous and ic, like ferrous and ferric, and cuprous and cupric, are added to the endings of the Latin name of an element, that indicates…
Lesser and greater charged ions of that element, respectively, of positively charged ions
(Iron II and III and Copper I and II)
-ide at the end of an element represent
Monoatomic anions
ex: Hydride, H-
Fluoride F-
Polyatomic anions that contain oxygen are called
When an element forms two oxyanions, the element with more oxygen ends in
The one with less oxygen end in
oxyanions
- ate
- ite
ex: nitrate - NO3-, nitrite NO2(-), Sulfate-SO4(2-), sulfite - SO3 (2-)
When a series of oxyanions contains four oxyanions, prefixes are also used. Which are used to inicate less and more oxygen, respectively?
Hypo and per
Ex: Hypochlorite: CLO(-) Chlorite: CLO2(-) Chlorate: CLO3 (-) Perchlorate: CLO4(-)
Polyatomic ions often gain one or more H+ ions to form anions of lower charge. The resulting ions are named by adding the words _____ and _____ to the front of the anions name.
An older method uses the prefix ___ to indicate the addition of a single hydrogen ion
Hydrogen and dihydrogen
bi
ex:
HCO3- —>Hydrogen carbonate or bicarbonate
HSO4 —-> Hydrogen sulfate or Bisulfate
H2PO4 —> Dihydrogen phosphate
Do metals generally form positive or negative ions?
What about nonmetals?
Metals generally form positive ions
Note: ions may contain metallic elements: chromate, CrO4 (2-) and permanganate, MnO4(-)
Nonmetals generally form negative ions
These two groups tend to form cations and and anions
Group IIA and VIIA, respectively, with +2 and -1 charges, respectively
The electrical conductivity of aqueous solutions is governed by the presence and concentration of ____ in solution
Ions
Pure water is a poor conductor.
A solute that dissolves completely into its constituent ions is called a…
Strong electrolyte
ex: NaCl, KI, HCl, in water
A solute that dissolves incompletely in aqueous solution and only some of the solute is present in ionic form is called
Weak electrolyte
Ex: weak acids like acetic acid, weak bases like ammonia, and HgCl2
Compounds that do not ionize at all in aqueous solution are called
Nonelectrolytes
Ex: Nonpolar gases, organic compounds, like oxygen and sugar
The number of moles per liter of solution is the
Molarity
The number of moles per kilogram of solvent is the
Molality
For dilute solutions at 25 degrees Celsius, the molarity of a solution is approximately _____ to the molality of a solution
Equal
The density of water at 25 degrees Celsius is 1kg per liter
The number of gram equivalent weights of solute per liter of solution is the…
Normality
The reactive capacity of a molecule is referred to as the
Gram equivalent weight, or equivalent
A 1 molar solution of sulfuric acid is how many normal in acid base reactions? Why?
2 because one mole of sulfuric acid donates 2 moles of H+
What is the equation solving for the concentration of a solution after dilution?
MiVi=MfVf
M= molarity, V = volume
What is the equation for ion product of a compound, Qsp?
[An+]m[Bn-]n
initial concentrations, not necessarily equilibrium
What is the expression for the solubility product constant for a saturated solution at equilibrium, Ksp?
The same as ion product
[An+]m[Bn-]n
What can be said about a solution who’s I.P. is equal its Ksp?
The solution is saturated
What can be said about a solution who’s I.P. exceeds it’s Ksp?
The solution is supersaturated and unstable
What can be said about a solution who’s I.P. is less than Ksp?
The solution is unsaturated and no precipitate will form
The solubility of Fe(OH)3 in an aqueous solution is determined to be 4.5*10^-10 mol/L. What is the Ksp for Fe(OH)3?
[Fe] = 4.5 *10^-10 M [OH] = 3*[Fe]
Ksp= [OH]^3*[Fe] = (3[Fe])^3 * [Fe]
= 27(4.510^-10)^4
What are the concentrations of each of the ions in a saturated solution of PbBr2 given that the Ksp of PbBr2 is 2.1*10^-6
Pb=x
Br=2x
Ksp=(x)(2x)^2
Ksp=4x^3=2.1*10^-6
x=8.0710^-3 M
2x=1.6110^-2 M
The Ksp of AgI in aqueous solution is 110^-16 mol/L. If a 110^-5 M soution of AgNO3 is saturated with AgI what will be the final concentration of the iodide ion?
1*10^-16 = [Ag] [I] (1*10^-16)/(1*10^-5) = [I]
[I] = 1*10^-11 mol/L
What is Chad’s calorimetric equation to solve for the heat required to raise a substance to a certain temperature with the specific heat?
q=mcΔT
