Exploring Substances: Acidic, Basic, and Neutral — Science STD 7 — Question

→ To use onions as olfactory indicators, you first need to prepare onion-infused strips by finely chopping onions and storing them overnight in a closed container with strips of clean cloth or filter paper.
 → The strips absorb the onion's distinct odor. When testing for acidity or basicity, place a few drops of an acidic solution, like lemon juice, on one strip and a basic solution, like baking soda, on another.
→ Observe the changes in odor. In acidic conditions, the onion smell might intensify or remain unchanged, while in basic conditions, the onion smell typically diminishes or alters, indicating the presence of a base.
 → This change in smell helps identify whether a substance is acidic or basic, making onions a simple olfactory indicator.