What is the typical pH range of an alkali?

An alkali is defined as a base that dissolves in water and produces hydroxide ions (OH⁻). This characteristic leads to the classification of alkalis as basic substances. The pH scale measures how acidic or basic a solution is, with values below 7 indicating acidity, values above 7 indicating basicity (or alkalinity), and a pH of 7 representing a neutral solution.

For a typical alkali, the pH range is greater than 7. Common examples include sodium hydroxide and potassium hydroxide, which have pH values significantly above 7 when in solution, often reaching up to 14 depending on their concentration.

Understanding the pH range of an alkali is important in various contexts, from chemical reactions to understanding environmental impacts. The other options present incorrect pH ranges for alkalis: values less than 5 signify acidic solutions, exactly 7 indicates a neutral solution, and values between 5 and 7 correspond to weakly acidic solutions, none of which align with the characteristic of alkalis being basic.