A pH or acid-base indicator is a compound that changes color depending on the pH of the substance that is added to it. Acids and bases make pH indicators turn different colors. Two substances that ...

Acids and bases are classes of materials that have different properties. Acid-base indicators change color depending on whether they are in acids or bases. Red cabbage leaves contain a substance ...

Acidic solutions have pH values less than 7. Stomach acid turns universal indicator paper a strong red colour. This indicates a pH value of 0, the strongest value of acid. Alkaline solutions have ...