CLASS 9 · LEARNING KNOWLEDGE
Acidic and basic solutions – basic principles
How it works
Acidic and basic solutions differ in their content of hydrogen ions (H⁺) or hydroxide ions (OH⁻), respectively. Acidic solutions contain more H⁺ ions than pure water, basic solutions more OH⁻ ions. The pH value indicates how acidic or basic a solution is. Acids and bases react differently with indicators and certain substances. Examples of acids are hydrochloric acid and citric acid; examples of bases are sodium hydroxide solution and ammonia solution.
Note
Acidic solutions contain an excess of H⁺ ions, basic solutions an excess of OH⁻ ions. The pH value is less than 7 for acids and greater than 7 for bases. Indicators show different colors in acidic and basic solutions.
Acidic solutions contain an excess of H⁺ ions, basic solutions an excess of OH⁻ ions. The pH value is less than 7 for acids and greater than 7 for bases. Indicators show different colors in acidic and basic solutions.
An example
Which statement applies to an acidic solution?
An acidic solution contains more H⁺ ions than OH⁻ ions. That is correct because the excess of H⁺ ions is the characteristic feature of an acid.
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50 Exercises
To the learning unit →Own explanation and own practice exercises by AmyMath. Subject reference framework: Chemistry. The topic assignment may vary by federal state.