higherpH

Higher pH refers to pH values above 7, indicating basic or alkaline conditions. The pH scale measures hydrogen ion activity in a solution; higher pH means lower hydrogen ion concentration. The scale ranges from 0 to 14 under standard conditions, with 7 neutral. Values above 7 denote basicity, while those below denote acidity.

Measurement and variability: pH is commonly measured with calibrated pH meters or chemical indicators. Temperature affects readings; pure water is neutral at 25°C with pH 7, but readings shift with temperature and dissolved substances. Concentrated bases can reach pH well above 12; common laboratory bases include sodium hydroxide and potassium hydroxide.

Causes and control: Alkalinity arises from dissolved bases such as hydroxide, carbonate, and bicarbonate, or from buffering systems. Natural waters and soils can maintain higher pH through carbonate minerals. pH can be raised by adding bases or lowered by acids; buffering resists rapid change.

Implications: In water treatment, higher pH reduces acidity but can cause scaling and corrosion; aquatic life has pH tolerances, typically around 6.5–8.5 for many species. In soils, high pH limits micronutrient availability (iron, manganese, zinc) and favors calcium and magnesium; liming is used to raise soil pH when needed.

Applications and safety: Alkaline pH is common in cleaning products, paper processing, textiles, and some chemical syntheses. High-pH solutions are caustic and can cause chemical burns; handle with gloves and eye protection and neutralize effluents before disposal.