(i) Plants and animals are pH sensitive. Living organisms can survive only in narrow range of pH change.
(ii) pH of the soil is important for plant growth. Plants require a specific pH range for their healthy growth.
(iii) pH in our digestive system: Our stomach produces hydrochloric acid that helps in the digestion of food. During digestion the stomach produces too much acid that cause pain and irritation.
(iv) Change in pH causes tooth decay. Tooth decay starts when the pH of the mouth is lower than 5.5. Tooth enamel gets corroded when the pH in the mouth is below 5.5.
(v) Self-defense by plants and animals through chemical warfare. Bee–sting leaves a chemical substance that causes pain and irritation. Applying a mild base like baking soda on the stung area provides relief. (Any three)
