Final answer:
Nitric acid (HNO3) is a corrosive mineral acid that causes chemical burns by decomposing proteins and fats in living tissues.
Step-by-step explanation:
A chemical nitric acid burn occurs when nitric acid (HNO3), a highly corrosive mineral acid, comes into contact with skin. Nitric acid acts as a strong oxidizing agent and can cause severe injuries. In case of skin exposure, it can lead to a second-degree burn. Nitric acid causes acid hydrolysis of proteins and fats, which decomposes living tissue. When concentrated nitric acid comes into contact with human skin, it can stain the skin yellow, due to its reaction with keratin. Due to its corrosive nature, it is important to handle nitric acid with caution to prevent chemical burns.