1) Caustic soda ltrs 2) Caustic soda, chemically 3) Caustic soda, symbolically 4) Caustic soda, to a chemist 5) Caustic soda, to chemists 6) Drain cleaner, chemically 7) Formula for lye 8) Lye in the lab 9) Lye, often 10) Soda, symbolically 11) Sodium hydroxide 12) Sodium hydroxide, chemically 13) Sodium hydroxide, to chemists Found on https://www.crosswordclues.com/clue/naoh