Final answer:
Salicylates, particularly acetylsalicylic acid or aspirin, are common chemicals found in many foods and used as pain relievers in various products.
Step-by-step explanation:
The chemical found in many foods and used in products such as aspirin and various pain relievers is salicylates. Specifically, acetylsalicylic acid, also known as aspirin, is widely recognized as an effective pain reliever and fever reducer. Willow tree leaves have been used for pain and fever relief for over 2,000 years because they contain salicylates, which are now synthesized and sold as aspirin. In addition to its analgesic and antipyretic uses, aspirin is an anti-inflammatory medication and is one of the most common medicines ingested by people worldwide.