Phosphonates contain C−PO(OR)2 groups, typically nonvolatile solids. Structurally related to phosphorous acid with tetrahedral phosphorus centers. Used as chelating agents in water softening and industrial applications
Phosphorous acid (H3PO3) is a diprotic acid with pKa 1.26-1.3. Solid HP(O)(OH)2 has tetrahedral geometry with P-H, P=O, and P-OH bonds. IUPAC recommends P(OH)3 as phosphorous acid, HP(O)(OH)2 as phosphonic acid
Fe(OH)2 is a white solid with greenish tinge from oxygen exposure. Produced by treating iron(II) salts with hydroxide ions. Forms brucite structure with Fe(II) centers bonded to six hydroxide ligands
Appears as yellow crystalline solid or grayish-white powder. Melting point is 480°C when decomposing. Commercial product contains about 20% water. Very hygroscopic and soluble in water
Colorless liquid with slightly sharp odor. Boiling point: 302.4°F at 760 mmHg. Melting point: 31.3°F. Density: 1.11 g/cm³ at 68°F. Miscible with water
Distilled water is made by boiling water until vapor and letting it condense. Glass bowl should float in boiling water without touching bottom. Process requires 45 minutes of boiling with ice. Distilled water is safe to drink but tastes flatter than tap water