AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
The stinging hair of nettle leaves injects methanoic acid (formic acid) into the skin, causing a burning sensation.
This is a standard 1-mark factual question from Chapter 2. Examiners accept either name: methanoic acid (IUPAC) or formic acid. Note: this fact is from the NCERT textbook context for Chapter 2, even though it does not appear explicitly in the provided passages — it is a well-known "Do You Know?" fact from that chapter. Write just the one line; no extra detail needed.