Caustic soda solid Molecular Formula: NAOH Molecular Weight: 40 CAS No.: 1310-73-2 H. S. Code: 28151100 Specification: NAOH: 96%min NACL: 2.8%max Na2Co3: 1.4%max Fe2O3: 0.008%max Specification: NAOH: 99%min NACL: 0.04%max Na2Co3: 0.5%max Fe2O3: 0.005%max