CAS Registry Number

CAS 104-15-4 — p-Toluenesulfonic acid

**p-Toluenesulfonic acid** is a strong organic sulfonic acid used as a catalyst in organic synthesis, a pH regulator in pharmaceuticals, and an electrolyte in batteries. It appears as a white crystalline solid with high solubility in water and organic solvents. CAS 104-15-4, molecular formula CH₃C₆H₄SO₃H, molecular weight 172.20 g/mol. Store at ambient conditions. Signal word: Danger (corrosive, harmful if swallowed or inhaled). Molekula supplies p-Toluenesulfonic acid from research to bulk quantities with full documentation and ISO 9001:2015 traceability.