Definition: pH is defined as the negative logarithm of hydronium ion concentration $-log(H₃O+)$, measured on a scale from 0 to 14.

Highlight: The relationship between pH and hydronium ion concentration is inverse - as pH decreases, $H₃O+$ increases.

Example: Different pH measurement methods offer varying levels of precision: pH paper provides ±1 unit accuracy, while pH meters offer ±0.1 unit precision.

Vocabulary: pH meter - an electronic device that measures the hydrogen ion concentration in a solution.

Quote: "The precision of pH measurements limits the significant figures in $H₃O+$ calculations to two digits."

Definition: An acid is a chemical species capable of donating a proton $H+$, while a base is a chemical species capable of accepting a proton.

Highlight: Water's unique role as an ampholyte allows it to act as both an acid and a base, making it central to acid-base chemistry.

Example: The reaction between carboxylic acid (CH₂COOH) and its conjugate base (CH₂COO-) demonstrates proton transfer in acid-base reactions.

Vocabulary: Ampholyte - a substance that can act as either an acid or a base depending on the reaction conditions.

Quote: "Carbon dioxide (CO₂) is a diacid capable of donating two H+ ions, forming various species including H₂CO₃ and HCO₃-."