LO 11 - 21

Question 1

Equation to calculate energy added to increase heat

Answer 1

q = m ⋅ Cs ⋅ Δ T
- m is mass
- Cs is specific heat

Question 2

Equation to calculate energy added to change state

Answer 2

q = n ΔH (state change)
- n is mols
- either ΔH fusion, vaporization

Question 3

You can tell what state is denser on a phase diagram based on the …

Answer 3

lean of the fusion curve; the state the curve leans TOWARDS is less dense

Question 4

What are the three sub-groups of crystalline solids?

Answer 4

Molecular, ionic, and atomic

Question 5

Solid with molecules as the composite units held together by the associated IMFS?

Answer 5

Molecular solids

Question 6

Molecular solids have ____ melting points

Answer 6

low

Question 7

Solid with ions as the units that are held together by strong coulombic bonds?

Answer 7

Ionic solids

Question 8

Ionic solids have ____ melting points

Answer 8

high

Question 9

Solid composed of individual atoms?

Answer 9

Atomic solids

Question 10

_________ atomic solids are held together by weak LDF and pack tightly to maximize interactions?

Answer 10

Nonbonding

Question 11

________ atomic solids are held together by metallic bonds contributing to the e sea

Answer 11

Metallic

Question 12

_______ _________ atomic solids are held together by covalent bonds in geometric structures

Answer 12

Network Covalent

Question 13

Nonbonding AS have ___ melting points
Metallic AS have ____ melting points
Network Covalent AS have ___ melting points

Answer 13

low, variable, high

Question 14

What are allotropes

Answer 14

forms of the same element in different arrangements. i.e. graphite or diamond

Question 15

Long chains-like molecules composed of repeating monomers

Answer 15

Polymers

Question 16

Monomer A + Monomer B = _______

Answer 16

Dimer

Question 17

Condensation polymers ______ atoms or small groups during polymerization

Answer 17

eliminate

Question 18

Addition polymers _____ _______ without elimination

Answer 18

link together

Question 19

The amount of a substance that will dissolve in a given amount of solvent

Answer 19

solubility

Question 20

solvent-solute > = solvent-solvent AND solute-solute interactions

Answer 20

solution generally forms

Question 21

solvent-solute < solvent-solvent and solute-solute interactions

Answer 21

solution may or may not form

Question 22

When two substances are soluble in each other in all proportions they are _____

Answer 22

miscible

Question 23

The energy to separate solute particles (ΔH solute) and solvent particles (ΔH solvent) from each other is always ______

Answer 23

endothermic, ΔH > 0

Question 24

Mixing the solute and solvent (ΔH mix) is an _________ process

Answer 24

exothermic, ΔH < 0

Question 25

What is Hess's Law

Answer 25

The enthalpy change of solution is the sum of its formation steps: ΔH solution = ΔH solute + ΔH solvent + ΔH mix

Question 26

For ionic compounds dissolved in water, ΔH solvent and ΔH mix are combined into one term called _______

Answer 26

heat of hydration (ΔH hydration)

Question 27

heat of hydration is always ______

Answer 27

exothermic

Question 28

For ionic compounds, ΔH solute = ______

Answer 28

-ΔH lattice

Question 29

Soulutions reach dynamic equilibrium when ______

Answer 29

rates of dissolution = recrystallization

Question 30

_________ solutions have dynamic equilibrium between dissolved and undissolved solute

Answer 30

saturated

Question 31

A solution containing less solute than equilibrium is _______

Answer 31

unsaturated

Question 32

A highly unstable solution containing more solute than equilibrium is ______

Answer 32

supersaturated

Question 33

The solubility of solids in water ______ with increasing temperature

Answer 33

↑ increases

Question 34

The solubility of gasses in water ____ with increasing temperature ____ with increasing pressure

Answer 34

↓ decreases ↑ increases

Question 35

Henry's Law

Answer 35

Solubility gas = Kh ⋅ P gas - Kh is a constant - P gas = P total ⋅ mol fraction gas

Question 36

Properties that depend on the number of particles dissolved in solution

Answer 36

colligative properties

Question 37

The VP of a nonvolatile nonelectrolyte + solvent is ____ the VP of pure solvent

Answer 37

less than

Question 38

Raoult's Law for the VP of a solution

Answer 38

P solution = X solvent ⋅ P solvent ( ⋅ i) - X mol fraction - VP pure solvent - Van Hoff factor if electrolyte

Question 39

What is Raoult's Law for two gasses?

Answer 39

P total = Pa + Pb Pa = Xa ⋅ P pure a Pb = Xb ⋅ P pure b

Question 40

Strong solute-solvent interactions in gasses cause a _______ deviation from Raoult's Law

Answer 40

negative

Question 41

Weak solute-solvent interactions in gasses cause a _______ deviation from Raoult's Law

Answer 41

positive

Question 42

The freezing point of a solution containing a nonvolatile solute is ____ than the freezing point of pure solvent

Answer 42

lower

Question 43

Equation for freezing point depression

Answer 43

ΔTf = m ⋅ Kf - ΔTf change in C relative to pure solvent - m is molality - Kf constant for solvent

Question 44

The boiling point of a solution containing a nonvolatile solute is _____ than the boiling point of pure solvent

Answer 44

higher

Question 45

Equation for boiling point elevation

Answer 45

ΔTb = m ⋅ Kb - ΔTb change in C relative to pure solvent - m is molality - Kb constant for solvent

Question 46

The pressure needed to stop osmotic flow

Answer 46

osmotic pressure

Question 47

Equation for osmotic pressure

Answer 47

Π = M ⋅ R ⋅ T - Π is osmotic pressure - M is molarity - R gas constant = 0.08206 - T in Kelvin