Acids, Bases, And Buffers Flashcards
Reactants combine to give __________.
Products
Products can fall apart to give ____________.
Reactants
___________ ____________ is the process of reactants combining to yield products and products breaking apart to yield reactants.
Dynamic equilibrium
When a system is a state of dynamic equilibrium is disturbed it will react to reestablish the equilibrium condition, this is called ______________________.
Le Chatelier’s principle
When is a system in a state of equilibrium?
When there is a balance between reactants and products.
What is balance defined by?
Thermodynamics
As the equilibrium constant (K) increases, the reaction favors _________, as K decreases, the reaction favors ________ ________.
Products, starting materials.
If you add products, the equilibrium will shift towards __________.
Reactants
If you remove products, the equilibrium will shift toward ________.
Products
An acid is a proton ________.
Donor
A base is a proton _________.
Acceptor
When an acid donates a proton, it is converted into its __________ _____.
Conjugate base.
When a base accepts a proton, it is converted into its __________ _____.
Conjugate acid
An ______________ _______ can behave as either an acid or a base.
Amphoteric species
H20 is an _______ ____.
Amphoteric species
The stronger the acid, the _______ the conjugate base.
The weaker the acid, the _______ the conjugate base.
Weaker
Stronger
A stronger acid is more determined to…
A stronger base is more determined to…
- give its proton to some base
- take a proton from some acid
Strong bases are _______ _____ _________.
Soluble ionic hydroxides
When a strong base dissolves in water…
It essentially all dissociates to ions.
Weak acids do or do not ionize 100% in water?
Do not (they establish equilibrium)
Weak bases establish equilibrium by ….
Accepting a proton from water.
The buffer in a solution …
Resists changes in pH
Buffers contain a _____ ______ and a _______ _____.
Weak acid, conjugate base
What equation is used to determine the ration of weak acid to its conjugate base at a given pH?
Henderson-Hasselbach
When the concentration of a weak acid and its conjugate base are equal, the pH is equal to ….
The pKa (Ka weak acids)
Nonionized drugs are _______ ________ and easily…
Lipid soluble, penetrate the blood/placental barriers.
The ionized form of a drug is…
Water soluble (hydrophilic)
The degree of ionization or nonionization determines …
Drug effectiveness.
What are the 3 steps of determination?
- 1 Is drug a weak acid or weak base?
- 2 What is pKa of drug? (reference)
- 3 pH target of solution (body)
Weak acids become _____ nonionized as pH falls.
More (H+ increases)
Acid + Acid = nonionized
Weak acids unite with _______ charged ions.
Positively (Na+, Mg++, Ca++)
What are salt drugs?
Na+, Mg++, Ca++
Recognize a salt drug as the base form of a…
Weak acid. (Sodium pentobarbital)
Weak bases become _____ unionized as pH >.
More (H+ decreases)
Base + Base = nonionized
Weak bases unite with _____ charged ions.
Negatively (Cl- SO4^2-)
If you recognize “drug” chloride, “drug” sulfate, they are the salt form of a
Weak base (lidocaine hydrochloride, morphine sulfate)
The ___________ drug penetrates the BBB and placental barrier.
Nonionized
The ___ the nonionized portion of the drug, the ___ the transfer to brain and fetus.
> ,>
3 Weak Acid Drugs:
- Thiopental
- Barbiturates
- Propofol??
4 Weak Base Drugs:
- Lidocaine (locals)
- Morphine (opioids)
- Versed (benzos)
- Propofol??
The pH of the fetus is _____ than maternal pH
Lower
The circulating nonionized drug does or does not cross the placental barrier?
Does
