Quiz 2 Acid Base Flashcards
In chemistry, what is a conjugate pair?
A weak acid and its conjugate base
Or a weak base and its conjugate acid
What is an example of a conjugate pair?
Carbonic acid and Bicarbonate
What is the mathematical formula for pH?
it is the negative log of hydrogen ion concentration
What is pKa?
pKa is an equilibrium constant
What does the Ka stand for in pKa?
acid dissasociation constant
What does the pKa tell us about the acid?
1.how tightly the proton is held onto by the acid
2. how easily the acid donates a proton
A stronger acid would have a (lower/higher) pKa?
Lower
A weaker acid would have a (lower/higher) pKa?
higher
What is the pKa of blood?
6.1
What pH does the carbonic acid-bicarbonate buffer system work most effectively?
6.1
How does a chemical buffer system prevent radical/large/rapid changes in pH and maintain homeostasis?
by dampening changes in hydrogen ion concentration in the case of excess acid or base
What does the term buffer action mean?
The ability of an acid base mixture to resist sudden/radical/rapid changes in pH
How do buffers work against large changes in pH?
By releasing or binding hydrogen ions in response to pH changes. Excess hydrogen ions will bind with bicarb to form carbonic acid
What is the main/only blood buffer of clinical significance?
Carbonic acid-bicarbonate buffer system
Name 2 other buffer systems in the body in regards to acid base balance
Plasma protein buffer system
Phosphate buffer system
Explain how the plasma protein buffer system works
The plasma protein buffer system works by having proteins with charged amino acid side changes binding to excess hydrogen ions when pH is too acidic and releasing hydrogen when pH is too basic
Describe the phosphate buffer system
Phosphate acts as a buffer by combining with hydrogen ions
what is the ratio between bicarbonate and carbonic acid under normal conditions?
20:1
What are the 3 variables that determine the effectiveness of a buffer system
- the pK of the buffer
- The quantity of the buffer
- Whether or not the buffer is in an open or closed system
Describe an open system in relation to buffers
In an open system, the products of buffering do not accumulate because they can be exhaled
An acid can be thought of as a proton _______
Donator
A base can be thought of as a proton _________
Acceptor
What are the two characteristics of a weak acid?
- Does not completely dissociate in water
- Smaller K and Ka values, larger pK values
Describe how bicarb functions in an open system and explain what occurs when bicarb buffers a hydrogen ion
When bicarb buffers a hydrogen ion, it reacts with excess hydrogen ions to neutralize them and convert them into water and carbon dioxide