P Chem Exam 2

Front 1

Colligative properties determined by

Back 1

-Intermolecular interactions

-Colligative properties is about how much SOLUTE you have

Front 2

4 colligative properties

Back 2

1. Vapor pressure lowering

2. Boiling point elevation

3. Freezing point depression

4. Osmotic pressure

Front 3

Ideal solution

Back 3

-Solution where there is no change in properties of components when mixed

-Formed by mixing components with similar properties

Front 4

Properties of ideal solution

Back 4

-No heat absorbed or released during mixing

-Final volume = sum of volume of components

-Properties are weighted averages of properties of pure components

Front 5

Attractive forces in ideal gases

Back 5

-Ideal gases have no attractive forces

-Molecules are so far apart they exert no intermolecular interaction on each other

-Truly ideal gases have 0 volume

Front 6

Attractive forces in ideal liquids

Back 6

-Ideal liquids have uniformity of attractive forces

-Impossible to have NO attractive forces

-Energy to break them up is equivalent

A-A = B-B = A-B

Front 7

Raoult's Law for Ideal Solutions

Back 7

PA = P°A × XA

Ptotal = PA + PB = P°A × XA + P°B × XB

P°= pure state

X= mole fraction

Front 8

Adhesive forces

Back 8

A-B interaction

-Prevents or reduces vaporization

-Solute-solvent

Front 9

Cohesive forces

Back 9

A-A or B-B interaction

-Solute-solute

-Solvent-solvent

Front 10

Cohesive forces > Adhesive forces

Back 10

-Positive deviation of Raoult's Law

-Total pressure increases

-A would rather react with itself than B so it can escape more easily

BEYONCE ESCAPING - BOY BYE

Front 11

Adhesive forces > Cohesive forces

Back 11

-Negative deviation of Raoult's Law

-Total pressure decreases

-A would rather react with B than itself so it is preventing evaporation

AINT LETTING BEYONCE GO

Front 12

Non-electrolytes

Back 12

-Do not ionize when dissolved

-Do not conduct electrical current

-Ex: sucrose, urea

-Colligative properties are the same

van't Hoff factor = 1

Front 13

Electrolytes

Back 13

-Forms ions in solution

-Different colligative properties than non-electrolyte

-Can be weak or strong

van't Hoff factor = the # ions in solution after dissociation (ex: NaCl = 2)

Front 14

van't Hoff i factor

Back 14

-Ratio of colligative properties of real solution to ideal solution

Takes into account:

- Behavior of ionic solutions

- Actual # particles in solution after electrolyte dissolves

-Activity coefficient --> electrolyte-solvent interaction

Is theoretically = to ions in solution after dissociation

Front 15

Boiling Point

Back 15

Temperature at which vapor pressure of liquid is = to external pressure of 760 mmHg

Front 16

Boiling point elevation

Back 16

Boiling point of solution - boiling point of pure solvent

∆Tb = imKb

Front 17

Ebullioscopic constant

Back 17

Kb = 0.51°C

Front 18

Freezing point depression

Back 18

∆Tf = imKf

Front 19

Cryoscopic constant

Back 19

Kf = 1.86°C

Front 20

Beckmann Method

Back 20

Just an FYI - this is a way to determine freezing point depression

Front 21

Two Vacuum Jacketed Flasks

Back 21

More accurate way to determine freezing point depression

-One flask : pure liquid with pure solid solvent

-Other : solution in equilibrium with pure solid solvent

Measure temp separately & calculate difference

Front 22

Semi-permeable membrane

Back 22

Allows passage of some solution components and not others

Front 23

"Perfect" semi-permeable membrane

Back 23

Allows passage of solvent

BUT NOT SOLUTE

Front 24

"Real" semi-permeable membrane

Back 24

Allows passage of solvent AND some solutes

Passage dictated by: size of solute & solubility of membrane

Front 25

Osmosis

Back 25

Process by which solvent moves thru semi-permeable membrane from pure solvent (low concentration of solute) to higher [ ] solute

*entropically driven

Front 26

Thistle tube

Back 26

Water moves into bulb w/concentrated solution & is pushed up tube til equilibrium is reached

π = pgh

p= density

g= gravity

h= height of soln above surface

Front 27

van't Hoff's Osmotic Pressure

Back 27

π = imRT

R = 0.082 L*atm/mol*K

note: KELVIN

Front 28

"Push-Pull" Delivery System

Back 28

Tablet with tiny laser cut orifice

-Drug mixed w/electrolyte inside semi-permeable membrane

-Water flows in through membrane

-Get swelling & polymer pushes drug out of orifice

entropically driven

Front 29

"L-OROS" Delivery System

Back 29

-Tablet or pump form

-Drug in solution in flexible chamber surrounded by solid matrix of salt (electrolyte) surrounded by a semi-permeable membrane

-Water flows in & pushes drug out

-Pushing out AND dissolution

entropically driven

Front 30

RBC in 0.9% saline

Back 30

Isotonic

-Cell is at equilibrium with saline

-Water flows in & out at same rate

-Cell remains normal & healthy

Front 31

RBC in 2% saline

Back 31

Hypertonic

-Water moves across membrane out of cell toward high NaCl [ ]

-Cells shrink (crenate)

-Water drives out of cell to restore equilibrium

Front 32

RBC in 0.2% saline

Back 32

Hypotonic

-Water moves into cell toward higher NaCl [ ]

-Cells swell & potentially lyse (burst)

-Water will go into cell to restore equilibrium

Front 33

2% Boric acid & RBC

Back 33

-BA has same tonicity as 0.9% NaCl

-In RBC will move from outside cell, into cell

*BUT!* BA will bring MORE H2O along with it --> starts swelling

Front 34

Tonicity of IV Fluids

Back 34

Normal = 280 - 290 mOsm/L

Fluid with osmotic pressure > 550 should be infused SLOWLY for safety

Front 35

Excess infusion of hypotonic IV fluids results in...

Back 35

-Hemolysis of RBC's

-Edema

-Convulsions

Front 36

Excess infusion of hypertonic IV fluids results in...

Back 36

-Dehydration

-Hypoglycemia

-Loss of electrolytes

-Coma

-Osmotic diuresis

Front 37

Factors for toxicity in IV medications

Back 37

-Derivation from tonicity

-# molecules in preparation

-Location of injection (ex: IV versus elsewhere)

-Volume & rate of injection

Front 38

Osmolarity of physiological fluids

Back 38

280-290 mosmol/kg

serum, tears, saliva

Front 39

Enteral nutrition products

Back 39

For patients with trauma & need the fluid they cannot eat

-hypertonic

Front 40

Results of giving nutritional product given IV:

Back 40

↓ blood pressure

Cardiac irregularities

Pulmonary edema

Cerebral hemorrhage

Front 41

Route of administration for nutrition products

Back 41

-Oral

-Gastric tube

-Direct instillation (port)- jejunum/stomach

Front 42

Hypertonicity in enteral meals

Back 42

-Hypertonic & hyperosmotic due presence of smaller molecules (AA, electrolytes) than what is normally in food

Front 43

Factors that impact tonicity of hypertonicity in enteral meals (from most to least)

Back 43

"Every cat sleeps on fluffy pillows forever"

1. Electrolytes

2. Complex sugars

3. Starches

4. Organic molecules

5. Flavorings/coloring

6. Proteins

7. Fats

Front 44

Imbalance of osmotic effect can lead to...

Back 44

-Cramping

-Nausea

-Vomiting

-Shock

**should be given slowly**

Front 45

Oral Rehydration Therapy (ORT)

Back 45

-Used in cases of severe fluid loss

-We talking severe vomiting/diarrhea, ok ok

-Focuses on glucose/Na+ transported in intestine (assist in bringing in H2O)

-Actually isn't all that great. Intestine getting rehydrated, but blood EVEN more dehydrated

-More dehydration & risk of death

Front 46

Food-based ORT

Back 46

-Chicken noodle soup to the rescue!

-Complex molecules in soup (protein, starch) have same effect as 1 single glucose molecule

-Enhance nutrient induced Na+ transport

-Rapid uptake at surface - avoids osmotic penalty

-Water & ions returned to blood quickly

-Extent & duration of diarrhea reduced!

Front 47

Isosmotic does not equal isotonic

Back 47

Boric Acid in the eyeballs - take home message:

-A solution containing a qty of drug calculated to be isoosmotic, is isotonic ONLY when the membrane under consideration is IMPERMEABLE to the solute & PERMEABLE to the solvent

Front 48

Sodium chloride equivalent values (E)

Back 48

-Kinda like conversion factor = 0.9

-By convention, 1 g of any drug that can replace the entire amt of NaCl in the solution will have a NaCl "E value" of 0.9

Front 49

How to prepare sodium equivalent (E)

Back 49

Step 1: From volume of solution, calculate total amt of NaCl needed to be isotonic

Step 2: Convert amt of drug/solute to equivalent in NaCl

Step 3. Subtract the difference between 1 & 2

Front 50

Partition coefficient

Back 50

-Equilibrium constant for partitioning process

-Some fraction will go into oil phase, some into water

Ko/w = [drug]oil / [drug]water

Front 51

Partitioning Process

Back 51

-Involves 2 immiscible liquids (immiscible to each other)

-Rate of the equilibrium [ ] of solute in solvent A & its equilibrium [ ] in solvent B

Ex of liquids: water (always), octanol, amyl alcohol, chloroform, CCl4

Front 52

Thermodynamic forces involved in partitioning?

Back 52

-Disruption of interaction of solute with water solvent

-Formation of bond between solute with oil

Front 53

Oil to Water partition coefficient

Back 53

-The standard nomenclature K o/w

K eq = [A] oil / [A] water

Warning: You can write the reverse but be careful of its meaning!

Front 54

What is an emulsion? Give 2 examples.

Back 54

The drug is trapped in a droplet & distributed throughout the preparation.

Ex. Oil drops in water --> Vinaigrette dressing, lotions

Ex. Water drops in oil --> mayonnaise, creams

Front 55

Two benefits of emulsions

Back 55

-Masks taste

-Improve absorption rate

Front 56

Yalkowsky and Valvani equation

Back 56

logS = -logK - 1.11 ((∆Sf (mp-25)) / 1364) + 0.54

S= aqueous solubility (mol/L)

K= oil to water part coeff (Ko/w)

∆Sf= molar entropy of fusion

mp= melting point (°C)

Front 57

∆Sf for non-rigid molecules with more than 5 non-hydrogen atoms

Back 57

13.5 + 2.5(n-5)

n= # of non-hydrogen atoms

Front 58

How does benzoic acid act as preservative?

Back 58

-Unionized form of benzoic acid can cross bacterial walls and acidify the bacteria

(not harmful to humans)

Front 59

Distribution of benzoic acid among oil/water phase depends on....

(3 things)

Back 59

Ko/w

Ka

q

Use equation:

C total = (K o/w * q + 1 + (Ka/[H+]) [HA]w

Front 60

Drug Action & Partition coefficient

Back 60

↑Ko/w = ↑ drug absorption

Front 61

Vaseline & mineral oil are examples of....?

Back 61

-When water solubility is so low that a significant concentration in water cannot be achieved, absorption may be negligible

-EVEN though there was a favorable partition coefficient

Front 62

Physical Barriers/Membranes

Back 62

-Skin 2-3mm thick, virtually water proof. Need fairly HIGH partition coefficient

-Buccal 40-50 cell layers

-Sublingual 100-200 um

-Intestinal not as complex

Front 63

Partition coefficient of drug depends on TWO Factors

Back 63

1. The polarity of the drug

2. The size of the drug (more lipophilic = higher partition coefficient)

Front 64

Concern of drug partitioning into plastics

Back 64

-Higher K o/w suggests drug will ESCAPE into or absorb into plastic tubing

-Reduces drug efficacy

-Result: you deliver unusually high doses to achieve efficacy

Front 65

Rule of thumb for drug partitioning/IV plastic

Back 65

↑Ko/w ↑ chances of leaching to PVC bags/tubing