EXPT 1: pH and BUFFER SOLUTIONS Flashcards
is a measure of the concentration of
hydrogen ions (H+
) in a solution.
PH
: a scale used to measure the
concentration of H+
ions in a solution, ranging
from 0 (strongly acidic) to 14 (strongly basic).
pH scale
pH is calculated using the formula
pH = -log[H+]
is the concentration of hydrogen
ions in moles per liter (M).
[H+] Acid
are mixtures of a weak acid
and its conjugate base, or a weak base and its
conjugate acid, that resist changes in pH
Buffer solutions
substances that donate H+
ions (protons) when dissolved in water.
Acid
a pair of
substances that differ by one proton.
Acid/conjugate-base pair
Base/conjugate-acid pair
substances that accept H+
ions (protons) when dissolved in water.
Bases
substances that increase the
concentration of H+
ions in a solution.
Acids
substances that increase the
concentration of OH ions in a solution.
Bases
completely dissociate in water,
releasing all their H+
ions.
Strong Acids
completely dissociate in
water, releasing all their OH ions.
Strong Base
partially dissociate in water,
releasing some of their H+
ions.
Weak Acids
partially dissociate in water,
releasing some of their OH ions.
Weak Base
substances that change color
in response to changes in pH.
PH indicators
a qualitative method that uses
a pH indicator to determine if a solution is
acidic or basic.
Litmus paper
a quantitative method that uses a
device to measure the pH of a solution
PH meters
a quantitative method that uses a
pH indicator to measure the pH of a solution.
PH paper
is a mixture of a weak acid and its conjugate base, or a weak base and its
conjugate acid, that resists changes in pH.
Buffers
consists of
carbonic acid (H2CO3) and its conjugate base, bicarbonate (HCO3-)
Carbonate buffer system
Function of the carbonate buffer system
regulates the pH of the blood by neutralizing excess H+ ions.
contain amino acids with acidic or basic side chains can act as buffers.
Proteins
consists of dihydrogen phosphate (H2PO4-) and its conjugate base, hydrogen phosphate, HPO4 2-
Phosphate buffer system
have a carboxyl group (-COOH),
Amino Acids
Function of Phosphate buffer system
regulates the pH of the cytosol of cells.
is deprotonated
when it reacts with OH to produce its conjugate base and water, decreasing the pH
The carboxyl group
is protonated when it reacts with H3O+ to produce its conjugate base and water, increasing the pH.
The amino group
is a mathematical equation that relates the pH of
a buffer solution to the concentrations of the
weak acid and its conjugate base.
The Henderson-Hasselbalch equation
a measure of the concentration of
hydroxide ions (OH-) in a solution
pOH
pH and pOH are related by the equation:
pH + pOH = 14
acid dissociation constant
pKa
concentration of the conjugate base
[A-]
concentration of the weak acid
[HA]
concentration of hydrogen ions in moles per liter (M)
[H+]
is crucial for proper
bodily functions, as even small changes can
lead to severe consequences.
Regulation of Blood pH
play a vital role in regulating blood pH by controlling the amount of carbon
dioxide (CO2) in the blood.
The lungs
the lungs decrease the rate and volume of
breathing to retain more CO2 in the body. This helps to increase the acidity of the blood.
Decreasing ventilation
the lungs
increase the rate and volume of breathing to
eliminate more CO2 from the body .This helps to reduce the acidity of the blood.
Increasing ventilation
an organ that also play a crucial role in
regulating blood pH by controlling the amount
of acid and bicarbonate in the blood.
The kidneys
The kidneys also reclaim
bicarbonate ions from the glomerular filtrate, which helps to increase the alkalinity
of the blood.
Reclaiming HCO3
The kidneys excrete excess
hydrogen ions (H+) from the blood, which helps to reduce the acidity of the blood.
Excreting acid
plays a crucial role in maintaining acid-base balance
in the bloodstream
The carbonic acid buffer system
act as a third type of blood buffer, containing both proton acceptors and
donors.
Protein buffer system
Understanding these buffer systems is essential in diagnosing and managing various
acid-base disorders
Clinical correlations
