pH Scale

Understanding pH Scale

• The pH scale is used to measure the acidity or alkalinity of a solution.
• The scale ranges from 0 to 14, where 0 is strongly acidic, 14 is strongly alkaline, and 7 is neutral.
• Each step on the pH scale represents a tenfold difference in acidity or alkalinity.
• Most biological processes occur at a pH close to 7.

pH Indicators

• pH indicators, such as litmus paper or universal indicator, are used to determine the pH of a substance.
• Litmus paper turns red in acid and blue in alkali.
• Universal indicator changes multiple colours across the pH scale to give a more precise pH value.

Acids and Bases on pH Scale

• Acids have a pH less than 7. The strength of the acid increases as the pH value decreases.
• Bases have a pH more than 7. The strength of the base increases as the pH value increases.
• Neutral substances like pure water have a pH of 7.

Impact of Concentration and Temperature

• The concentration of the hydrogen ions (H+) or hydroxide ions (OH-) in a solution determines its pH.
• Temperature can also affect the pH, although this is less commonly considered in basic studies.

Role of pH in Everyday Life

• pH plays a crucial role in everyday life from digestive systems to gardening to swimming pools.
• Many products, such as cleaning supplies or cosmetics, have pH values indicated on their labels.
• Hydrangeas, for instance, change colour based on the pH of the soil they are grown in.
• It is essential to maintain a certain pH in swimming pools to prevent bacterial growth and maintain skin health.