Unit 3: Intermolecular Forces and Properties

Question 1

Ion-Ion Forces

Answer 1

Attraction between oppositely charged ions. (Strongest IMF due to straight + & - attraction)

Question 2

Ion-Dipole Forces

Answer 2

Attraction between an ion and a polar molecule. (Ex: NaCl dissolving in water)

Question 3

Dipole-Dipole Forces

Answer 3

Attraction between polar molecules (- is attracted to +)

Question 4

Hydrogen Bonding

Answer 4

A stronger form of Dipole-Dipole forces. Involves a polar hydrogen and a polar N, O, or F

Question 5

London Dispersion Forces (LDF)

Answer 5

IMFs between a nonpolar molecule and something else. Induced Dipole-Induced Dipole (ID)
Ion-ID
Dipole-ID

Question 6

Polarizability

Answer 6

Means, how easy it is to induce a dipole?
The bigger an atom, the more polarizable. (Softer)
Smaller atoms-highly nonpolarizable (Harder)

Question 7

List of IMF Strength. Rank from Strongest IMFs to Weakest.

Answer 7

Ion-Ion (Strongest), Ion-Dipole (2nd Strongest), Hydrogen Bonding, (3rd Strongest), London Dispersion (Weakest)

H Bonds are either the strongest or the 2nd strongest.

Question 8

Ionic Solids have…

Answer 8

Ionic Bonds, Strong Ionic forces, brittle, and high melting point. [conducts electricity when dissolved only] (ex. NaCl, MgO)

Question 9

Covalent Network Solids have…

Answer 9

Layered networks, are Rigid, very Hard, and DO NOT conduct electricity (ex. diamond, graphite)

Strongest Covalent Forces

Forms some of the hardest things that exist.

Question 10

Molecular Solids have…

Answer 10

weaker IMFs, are softer, and have lower melting points.

Question 11

Metallic Solids have…

Answer 11

sea of electrons, are good conductors of heat and electricity, malleable and ductile.

Question 12

Crystalline solids have…

Answer 12

A nice orderly, grid structure

Question 13

Amorphous solids have…

Answer 13

a random structure.

Question 14

Ideal Gas Law Equation

Answer 14

PV=NRT or (Pressure)(Volume) = (Moles)(Gas Constant)(Temperature)

Question 15

What is Dalton’s Law of Partial Pressures

Answer 15

When you have a mixture of gasses, the full pressure is the sum of the partial pressures, (ex. gas collection over water)

Question 16

What is the equation for Dalton’s Law of Partial Pressures.

Answer 16

P[total] = P[a] + P[b] + P[c]… (a, b, c are gasses. If there are more gasses in a mixture, add more Pressures (P), if less, then remove (P)s.

Question 17

What is Charles’ Law

Answer 17

Relationship between Temperature and Volume, as Temp increases, Vol increases. Equation is [V = kT V/T = k]

Question 18

What is Boyle’s Law

Answer 18

Relationship between Volume and Pressure. More Pressure = Lower Volume. Lower Pressure = More Volume Equation (P[1]V[1] = P[2]V[2])

Question 19

What is Combined Gas Law

Answer 19

Combines Charles’, Boyle’s, and Gay Lusac’s Law. Used to calculate changes when other things are kept constant.
(ex. Assuming constant temp, if a 1L container of gas at a pressure of 0.32 atm is constrained to 0.25L, what is the new pressure?
Equation is (P1V2)/T1 = (P2V2)/T2)

Question 20

What is Kinetic Molecular Theory

Answer 20

A theory that helps describes why gasses act the way they do. KMT assumes that gasses follow these rules.
*Gas moves in random directions at relatively large distances
*Collisions are perfectly elastic (no energy loss)
*Gasses move in straight lines until colliding with the side of a container
*Average Kinetic Energy of a sample of gas is proportional to Temperature.

Question 21

What is a Solution?

Answer 21

Solutions (also known as homogenous mixtures) are a combination of any matter. (ex. NaCl and H2O)

Question 22

Difference between a Solvent and a Solute?

Answer 22

Solvents are the largest quantity in a solution and is what is used to dissolve Solutes.
Solutes are the smallest quantity in a solution and dissolve in in the Solvent

Question 23

What is Solvation?

Answer 23

The process of mixing a solvent and solute.

Question 24

Equation for Object in motion. (May come in handy)

Answer 24

K = 1/2 (mv) squared
Kinetic Energy = 1/2 (mass x velocity)[squared]

Question 25

What do Maxwell Boltzmann Diagrams show

Answer 25

Shows distribution of molecules moving at a certain speed.

Question 26

When do gasses differ from Ideal Gas Law

Answer 26

When gasses are at... *High Pressure, gas molecules start to take up more space *Low Temperature, IMFs start to take effect ...they start to differ from the Ideal Gas Law. This is called Van der Waals equation (Likely will never ever be used in AP Chemistry).

Question 27

What is Molarity?

Answer 27

Molarity is the measure of a solute's concentration in a solution. Molarity Equation= Moles of solute /Liters in solute, M = m/L *Basically moles per liter

Question 28

What is a Suspension or Mechanical Mixture?

Answer 28

A heterogenous mixture of two or more substances, (ex. sand and water)

Question 29

What are the properties of a Suspension/Mechanical Mixture

Answer 29

*Sizes, shapes, and concentrations of particles can vary in a Suspension. *Macroscopic properties are different at different locations within the sample. *In some cases, components can be separated through filtration.

Question 30

What are the properties of a Solution or Homogenous Mixture?

Answer 30

*Have a mix of 2 or more substances *Macroscopic properties do not vary within sample *Components cannot be separated through filtration *Components can be separated by methods that alter IMFs *No components are large enough to scatter visible light

Question 31

When does a Solution become a Saturated Solution?

Answer 31

When the solvent has dissolved the max amount of solute possible at a certain temp, and some solid particles remain undissolved. Becomes an equilibrium system where solid particles continually dissolve in the solvent and dissolved particles fall out of the solution.

Question 32

What are 3 different types of Solutions?

Answer 32

Liquid Solutions, Solid Solutions, and Gas??? *Check*

Question 33

Properties of Solid-Liquid Solutions

Answer 33

*Many ionic compounds dissolve in polar solvents (ion-dipole) *Polar solids, such as glucose, dissolve in polar solvents (dipole-dipole or H-bonds) *Nonpolar solids, such as mothballs dissolve in nonpolar solvents (dispersion

Question 34

What are the Properties of Steel?

Answer 34

*Pure Iron lacks directional bonds *Steel is more rigid, less malleable, and less ductile than pure iron because of stronger directional bonds between C and Fe *Density of Steel is greater than that of pure Fe, as interstitial atoms do not expand by much

Question 35

What are 2 equations that express concentration?

Answer 35

Molarity (M) = moles solute / liters solution Or... mole fraction = X[a] = moles A / moles A + moles B + moles... *note, molarity can change with temperature, mole fractions do not change with temperature.

Question 36

What do Particulate models do?

Answer 36

Particulate models represent interactions between components of a mixture, like... Ion sizes and orientation of solute ions and solvent particles and represent concentrations of components.

Question 37

What is Dilution

Answer 37

decreasing concentration by adding solvent (typically water) M1V1 = M2V2

Question 38

What is Distillation

Answer 38

Distillation separates mixtures by taking advantage of boiling points and differences in vapor pressure. (ex, 1 liquid A boils at 70 C, Liquid B at 700 C, Liquid A will evaporate first, being collected as a vapor, separating the liquids.)

Question 39

What is Paper Chromatography

Answer 39

Paper Chromatography separates mixtures by taking off polarity and non polarity.

Question 40

What are the Solubility Rules you should know

Answer 40

*Group 1A elements are Na+, K+ etc *Salts of nitrate and ammonium *Hydroxide + IA or IIA *Silver compounds usually insoluble *Cl-, Br-, I-, exceptions, Ag+, Pb2+, Hg *Memorizing these aren't too important *"Like dissolves like" - Ms. Horgan Polar solvents dissolve polar solvents, nonpolar solvents dissolve nonpolar solvents

Question 41

Shorter wavelengths have ___ frequency and ___ energy

Answer 41

Shorter wavelengths have higher frequency and higher energy

Question 42

Longer wavelengths have ___ frequency and ___ energy

Answer 42

Longer wavelengths have lower frequency and lower energy

Question 43

Equations for Light

Answer 43

h= Planck's Constant = 6.626 x 10 (-34 exponent) Js

Question 44

Light Quantification equation?

Answer 44

E = hv Energy of a Photon = Planck's constant x energy.

Question 45

Do different color lights have different energies and properties?

Answer 45

Yes. Red lights have lowest energy, Green and Blue have most.

Question 46

What is Beer's Law of Absorption?

Answer 46

Relationship between chemical solution and absorption of light. concentration of chemical solution is directly proportional to absorption of light Equation is A=abc *A=Absorption *a=molar absorptivity b=path length c= solute Used to find concentrations.