pHtaseme

pHtaseme refers to the acidity or basicity of a solution, expressed as a pH value on the pH scale. The pH value is the negative base-10 logarithm of the activity of hydrogen ions in the solution. At 25°C, the pH scale typically runs from about 0 to 14, with 7 neutral; values below 7 indicate acidity and values above 7 indicate basicity (alkalinity). Temperature changes can shift measured pH and the effective range of the scale.

Common methods to determine pH include electronic pH meters with glass electrodes and colorimetric indicator kits or test strips. For accurate results, meters are calibrated with standard buffers (commonly pH 4, 7, and 10) at the measurement temperature; samples should be well mixed, free of turbidity, and the electrode kept in good condition. Ionic strength and interfering substances can affect readings.

pH level influences chemical reactions, solubility of compounds, and biological processes. In medicine and biology, blood pH is maintained around 7.35–7.45; in agriculture, soil pH governs nutrient availability; in environmental science, pH changes in rivers and lakes indicate pollution or acid rain; in food and beverage production, pH affects flavor, texture, microbial growth, and shelf life.

Common reference values include citric juice around pH 2–3, human blood around 7.35–7.45, seawater around 8.1, household bleach around 12, and gastric juice around 1–3.