Substances can be classified as acidic or alkaline based on their pH levels. An acidic substance typically has a pH value of less than 7, while alkaline substances have a pH value greater than 7.
Common acidic substances include:
- Acids: Such as hydrochloric acid (found in stomach acid), sulfuric acid, and acetic acid (vinegar).
- Citrus Fruits: Like lemons and oranges, which contain citric acid.
- Carbonated Beverages: These often contain carbonic acid due to the dissolution of carbon dioxide in water.
On the other hand, typical alkaline substances consist of:
- Base Compounds: Such as sodium hydroxide (lye) and potassium hydroxide.
- Natural Alkaline Foods: Like spinach, kale, and other leafy greens which can help to alkalize the body.
- Water: Especially when it has been treated or has a high mineral content, can be alkaline.
Understanding whether a substance is acidic or alkaline is important because it can influence various chemical reactions and biological processes, such as digestion and overall health.