{"id":69512,"date":"2026-11-13T04:14:04","date_gmt":"2026-11-12T19:14:04","guid":{"rendered":"https:\/\/phys-edu.net\/wp\/?p=69512"},"modified":"2026-11-13T04:14:04","modified_gmt":"2026-11-12T19:14:04","slug":"the-fizz-is-co%e2%82%82-watch-10-hydrochloric-acid-melt-away-water-stains","status":"publish","type":"post","link":"https:\/\/phys-edu.net\/wp\/?p=69512&lang=en","title":{"rendered":"The Fizz Is CO\u2082! Watch 10% Hydrochloric Acid Melt Away Water Stains"},"content":{"rendered":"

Hi, I’m Ken Kuwako, your Science Trainer. Every day is an experiment.<\/strong><\/span><\/p>\n

Sanpoul, a popular toilet cleaner in Japan, wipes away stubborn limescale like magic. But which ingredient is actually doing the work? Sanpoul also contains surfactants and other additives, which raises a fair question: “Can hydrochloric acid really do this all by itself?” So this time, I poured plain hydrochloric acid straight onto limescale to catch the culprit red-handed.<\/p>\n

A Quick Look Inside Sanpoul<\/h3>\n

Sanpoul contains hydrochloric acid at a concentration of about 9.5%.<\/p>\n

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Its main job is most likely to dissolve calcium carbonate, the main component of limescale, and calcium phosphate, the main component of the urine scale that builds up in toilets.<\/p>\n

That said, Sanpoul also contains surfactants and other ingredients. Surfactants help the liquid spread and cling to the surface of the grime. That made me wonder: is the hydrochloric acid really the one removing the dirt, or are the surfactants playing a big part too?<\/p>\n

What Happens When We Pour On 10% Hydrochloric Acid?<\/h3>\n

So I poured 10% hydrochloric acid, which is almost the same concentration as Sanpoul, onto some limescale.<\/p>\n