CH2 CHEM PT 2 - pH &BUFFERS -

Vocabulary flashcards covering key terms and concepts from the lecture notes on pH, acidity, buffers, and the bicarbonate buffer system.

pH

A measure of how acidic or basic a solution is, on a 0–14 scale with 7 being neutral; higher numbers mean fewer hydrogen ions (more basic), lower numbers mean more hydrogen ions (more acidic).

Hydrogen ion (H+)

A positively charged ion whose concentration determines acidity; more H+ means more acidic; pH is the negative logarithm of [H+].

Ion

An atom or molecule with a net electric charge due to loss or gain of electrons.

Homeostatic pH range (blood)

The normal blood pH range is 7.35–7.45; deviations can disrupt physiological processes.

Neutral pH

pH = 7; neither acidic nor basic.

pH unit change and H+ concentration

Each unit change in pH corresponds to a tenfold change in hydrogen ion concentration; higher pH = 10x fewer H+, lower pH = 10x more H+.

Denaturation

Unfolding of proteins due to changes in pH or temperature, leading to loss of function.

Buffer

A system that resists changes in pH by donating or removing hydrogen ions; composed of a weak acid and its conjugate base.

Weak acid (buffer component)

The acid portion of a buffer that can donate hydrogen ions to raise [H+].

Conjugate base (buffer component)

The base portion of a buffer that can remove hydrogen ions from solution, increasing pH.

Bicarbonate–carbonic acid buffer system

Major blood buffer using carbonic acid (H2CO3) and bicarbonate (HCO3−) to maintain pH via the equilibrium H2CO3 ⇌ H+ + HCO3−.

Carbonic acid (H2CO3)

A weak acid in the bicarbonate buffer that donates H+ when needed to lower pH.

Bicarbonate (HCO3−)

Conjugate base of the bicarbonate buffer that can remove H+ to raise pH (form carbonic acid).

Vomiting and pH balance

Loss of stomach acid from vomiting tends to raise pH (become more basic); buffers counteract to restore normal pH.

H2CO3 ⇌ H+ + HCO3− (buffer reaction)

Equilibrium showing carbonic acid dissociating to release H+ and bicarbonate; bicarbonate can remove H+ to reduce acidity, carbonic acid can donate H+ to increase acidity.

Molar (M)

Unit of concentration: moles per liter (mol/L); used to express [H+] in pH calculations.