acids bases and buffers week 2

Question 1

Dynamic Equilibrium

Answer 1

reactants combine to give products, products can fall apart to give reactants.

Question 2

Le Chatelier’s Principle

Answer 2

When a system in a state of dynamic equilibrium is disturbed, it will react to re-establish the equilibrium condition
Nature likes being in an equilibrium state
Changing reaction conditions (concentrations, temperature, etc.) moves the system away from being at equilibrium
The system will adjust (go forwards or backwards) until it again is in an equilibrium state

Question 3

Hemoglobin (Hb) is the protein in blood that carries oxygen from the lungs to the rest of the body
Hb combines reversibly with oxygen in the lungs

Answer 3

In cellular tissue, the concentration of oxygen is low, and the system perceives this as removing a reactant. Therefore, the equilibrium shifts toward starting materials, trying to replace the missing reactant, oxygen. So it is in accordance with Le Châtelier’s principle that hemoglobin loads up on oxygen in the lungs and dumps oxygen into the cells.

Question 4

The Equilibrium Constant

Answer 4

A system is in a state of equilibrium when there is a balance between reactants and products
This balance is defined by thermodynamics
The equilibrium constant is the numerical description of that balance

Question 5

Meaning of K

Answer 5

As K increases, the reaction tends to increasingly favor products
As K decreases, the reaction tends to increasingly favor starting materials (the reverse reaction becomes more favorable)

Question 6

example of k

Answer 6

Carbon monoxide kills by tying up the hemoglobin so that not enough oxygen can be delivered to the body. The equilibrium constant for hemoglobin and carbon monoxide is about 200 times larger than the equilibrium constant for hemoglobin and oxygen. Therefore, when carbon monoxide is present, a greater percentage of the hemoglobin is in the carboxy form,because the equilibrium position is further to the product side. This means there is less free hemoglobin available to bind oxygen.

Question 7

Subscripts are

Answer 7

The equilibrium constant (K) is often appended with a subscript
The subscript denotes the type of equilibrium reaction

Question 8

k subscript examples.

Answer 8

Keq is a generic equilibrium constant
Ka is for weak acids
Kb is for weak bases
Ksp is for solubility

Question 9

Solids and Liquids concentration

Answer 9

The concentration of a pure solid or liquid is a constant value (or very nearly so)

Question 10

Changing Concentration- If you add products what will happen

Answer 10

the equilibrium will shift toward reactants

Question 11

Changing Concentration- If you remove products what will happen

Answer 11

the equilibrium will shift toward products

Question 12

The most generally useful definition of an acid is the Brönstead definition. Does it state that?

Answer 12

An acid is a proton (hydrogen ion), donor
Examples: HCl, H2SO4
A base is a proton (hydrogen ion), acceptor
Examples: NaOH, NH3

Question 13

When an acid donates a proton, it is converted into its

Answer 13

conjugate base,

When an acid gives away a proton, it always gives it to a base, because a proton is a much too concentrated charge to float around unnoticed and alone in a solution

Question 14

When a base accepts a proton, it is converted into its

Answer 14

conjugate acid

Question 15

The H+ ion is a proton
Chloride ion has special relationship with HCL
what are they togeather?

Answer 15

They are conjugate acid-base pairs

Question 16

Amphoteric (Amphiprotic) Species what is an example

Answer 16

An amphoteric species can behave as either an acid or a base

H2O is an amphoteric species

Question 17

Relative Strength of Acids and Bases

Answer 17

The stronger the acid, the weaker the conjugate base

The weaker the acid, the stronger the conjugate base

Question 18

Ionization Equilibria of Weak Acids

Answer 18

Weak acids do not ionize 100% in water

Weak acids establish an equilibrium …

Question 19

Ionization Equilibria of Weak Bases

Answer 19

Weak bases establish an equilibrium by accepting a proton from water …

Question 20

The pH Scale

Answer 20

The pH scale quantitatively describes the “acidity” or “alkalinity” of a solution
pH = 7 defines the neutrality point
pH < 7 defines an acidic solution
pH > 7 defines a basic solution
The pH scale is based on the self-ionization of water
pH is defined by the equation

Question 21

The meaning of K

Answer 21

A system is in balance (equilibrium) when there is a balance between the reactants and products.
K is the equilibrium constant which provides a numerical description of that balance.
As K increases, the reaction tends to increasingly favor the products. As K decreases, the reaction tends to favor the starting materials.

Question 22

ph Buffers

Answer 22

A pH buffer is a solution that resists changes in pH
A pH buffer may contain a weak acid (HA) and its conjugate base (A-)

So, when a small amount of a strong acid or base is added to the solution, the pH will change, but not nearly as much as with an unbuffered solution.

Question 23

simplified meaking of k

Answer 23

50% of drug will be ionized 50% will not. this is also the pKa number.
example drug with a pKa of 7.7 is 50% ionized

Question 24

is an acid ionized?

Answer 24

yes

Question 25

is a base non- ionized?

Answer 25

yes

Question 26

Drug utilization by the body is determined by

Answer 26

the degree of ionization/nonionization.

Question 27

The nonionized drug is lipid-soluble and readily penetrates the blood-brain and placental barriers. T/F

Answer 27

true

Question 28

The ionized form of a drug is

Answer 28

water-soluble (hydrophilic).

Question 29

Knowing the degree of ionization or nonionization determines

Answer 29

drug effectiveness.

Question 30

3 Steps of Determination

Answer 30

Is the drug a weak acid or a weak base?
What is the pKa of the drug? (This is your reference).
The pH of the target solution the drug is placed in? (Usually the body where the pH is 7.4).

Question 31

Is the drug a weak acid or a weak base?

Answer 31

Once you know if you have a weak acid/base, you will know how the drug will behave when the pH changes.
Weak acids become more nonionized as pH falls (H+ increases

Question 32

Acid + Acid = nonionized

Answer 32

true

So….if you see a salt drug i.e. sodium drug, calcium drug, magnesium drug you would recognize the drug as the salt base form of a weak acid. Sodium pentobarbital is a salt of a weak acid.

Question 33

Is the drug a weak acid or a weak base?

Answer 33

Weak bases become more unionized as pH increases (H+ decreases).

Question 34

Weak bases become more unionized as pH increases (H+ decreases).

Answer 34

true

Question 35

Base + Base = nonionized

Answer 35

If you were to see salts: “drug” chloride, “drug” sulfate, recognize them as the salt form of a weak base.
Lidocaine hydrochloride and morphine sulfate are salts of weak bases.

Question 36

What is the pKa of the drug? weak acids

Answer 36

The pKa of a weak acid is the pH at which 50% is ionized and 50% is nonionized

The nonionized drug penetrates the blood brain barrier and placental barrier. The greater the nonionized portion of the drug, the greater the transfer to brain and fetus.

Question 37

What is the pKa of the drug?Weak Bases:

Answer 37

The pKa is different for each weak base.
The nonionized form of a weak base is the base and the ionized portion is the conjugate acid.
A substance that accepts a hydrogen ion is said to be “protonated”

Question 38

Trapping of local anesthetics in fetal circulation.

Answer 38

The pH of the fetus is lower than maternal, the circulating nonionized drug crosses the placental barrier. Once in the fetus, equilibrium is reestablished, with a greater % ionized and trapped in fetal circulation.

Question 39

what does soda-lime neutralize

Answer 39

co2

Question 40

for every 100 liters of soda-lime how many liters of co2 is absorbed.

Answer 40

23 liters

size should be 2.5 mm

Question 41

optimal mesh screen size is?

Answer 41

• 4.8 loosly packed.

Question 42

what color is it soda life if its all used up and how to fix the increase in co2

Answer 42

violet purple and increase your inspired o2. ph sensative dye

Question 43

pulse ox is what law

Answer 43

bear lambert law. spectrophotosynthesis 660 nanometers . 2 wave lengnths of light.

changes in the absorption of light through the vascular bed.

infrared light is 940 nanometers

Question 44

what compounds in the blood can mess with the pulse ox?

Answer 44

meth hemoglobin. sat reads at constant 85%

and carboxyhemoglobin can read above the normal.

Question 45

what will methaline blue do to the sat?

Answer 45

interrupt it for like 3-5 minutes