Understanding pH in Water Quality

pH

Measure of acidity or alkalinity in water.

Acids

Substances that donate protons (H+) in solutions.

Bases

Substances that accept protons (H+) in solutions.

Arrhenius Acids

Produce H+ ions in aqueous solutions.

Arrhenius Bases

Produce OH- ions in aqueous solutions.

Brønsted Acids

Proton donors in acid-base reactions.

Brønsted Bases

Proton acceptors in acid-base reactions.

Lewis Acids

Electron pair acceptors in chemical reactions.

Lewis Bases

Electron pair donors in chemical reactions.

Strong Acids

Ionize completely in solution, e.g., HCl.

Weak Acids

Partially ionize in solution, e.g., CH3COOH.

Multiprotic Acids

Can donate more than one proton.

Water Dissociation

Equilibrium between water, H+, and OH-.

pH Calculation

pH = -log[H+], determines acidity.

Phenolphthalein

Common pH indicator for alkalinity.

Litmus Paper

Paper that changes color with pH.

Acid Mine Drainage

Acidic water from mining activities.

Flint Water Crisis

Lead leaching due to low pH water.

Orthophosphate

Used to inhibit corrosion in drinking water.

Disinfection Byproducts

Chemicals formed during water disinfection.

pH Water Quality Criteria

Standards for acceptable pH levels in water.

Activity vs Concentration

Activity accounts for interactions in solution.

Chemical Speciation

Distribution of chemical species in solution.