pH and pKa
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- What is the normal pH in blood
- 7.4
- Define the ion product of H20
-
It is the [H+]*[0H-] = Kw
Kw= [H+][0H-] = [H20]*Keq - What is the ion product of H20 at 25 deg celcius
- 1e-14
- When is a solution of water said to be neutral
- When [H+]=[0H-]
- What is pH?
- It is the negative logarithm of the [H+]
- What is an acid?
- A proton donor
- What is a base?
- A proton acceptor
- What is Ka?
- ([H+][A-])/[HA] = Ka
- The stronger the tendency to give up a proton, the _____ the acid, the _______ the pKa
- stronger; lower
- What is titration?
- A method used to determine the amount of acid in a given solution
- What is a buffer?
- A mixture of weak acids and their conjugate base that tend to resist changes in pH when small amounts of acid or base are added.
- When is the buffering power of a system maximal.
- When [HA] = [A-]
- What is the pKa of a buffer system?
- The pH at which [HA]=[A-]
- Why does the addition of strong acid or base to a buffer not result in a large pH change
- Because the ratio of the concentration of the conjugate base to the acid only changes very slightly
- What is the H-H equation?
- pH=pKa + log([A-]/[HA])
- What happens when the [H+] increases in the blood?
- Increased H2C03; Increased dissolved C02; Increased gaseous C02 -> Excess C02 gas is exhaled
- What happens when blood plasma pH increases?
- Decreases H2C03, dissociates into H+ and HC03-; causes C02 gas to dissolve in blood plasma
- The pH of a bicarbonate buffer system ultimately depends on what?
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1.The concentration of HCO3- in the aqeous phase
2.The partial pressure of C02