* pH Scale: The pH scale measures the acidity or alkalinity of a solution. It ranges from 0 to 14, with:
* 0-6 being acidic
* 7 being neutral (like pure water)
* 8-14 being alkaline (or basic)
* Inorganic Acids: Inorganic acids are a common source of acidity. Examples of inorganic acids with a pH around 4 include:
* Hydrochloric acid (HCl): A strong acid commonly used in laboratories.
* Phosphoric acid (H3PO4): Found in fertilizers and soft drinks.
* Acetic acid (CH3COOH): The main component of vinegar.
Important Note: The specific inorganic compound with a pH of 4 will depend on its concentration. A dilute solution of a strong acid might have a pH of 4, while a more concentrated solution of a weak acid might also have a pH of 4.
