Solfuric acid 20%
| Formula: | H2O4S |
| Chemical formula: | H2SO4 |
| Density: | 1.84 g/cm3 (20 °C) |
| Molar mass: | 98.08 g/mol |
| CAS number: | 7664-93-9 |
| EC index number: | 016-020-00-8 |
| HS code: | 28070010 |
| EC number: | 231-639-5 |
| Storage (temperature): | Without limitations. |
| SDS | available |
| RTECS: | WS5600000 |
| R phrase: | R 35 |
| S phrase: | S 26-30-45 |
| Odour: | odourless |
| Form: | liquid |
| Color: | colourless |
| PH value: | 0.3 (49 g/l 25 °C) |
| Solubility in water: | (20˚C) soluble, |
| Solubility in ethanol: | soluble, |
| Boiling point: | ~ 335 °C |
| Melting point: | ~ 3 °C |
| Vapour pressure: | ~ 0.0001 hpa (20 °C) |
| Thermal decomposition: | ~ 338 °C |
| Viscosity dynamical: | ~ 24 mPa*s (20 °C) |
| Assay | 19.0 – 21.0 | % | |
| Description | Conforms | ||
| Solubility | Conforms | ||
| Identification | Conforms | ||
| Chloride | ≤ | 0.005 | % |
| Heavy metals | ≤ | 5.0 | ppm |
| Residue on ignition | ≤ | 0.005 | % |
| Reducing Substances | Conforms |
Sulfuric acid 20% is a diluted aqueous solution of sulfuric acid commonly used in laboratories and pharmaceutical processes where a moderately strong acid is required with reduced corrosiveness compared to concentrated acid.
🏭⚗️ Production
It is prepared by carefully diluting concentrated sulfuric acid with distilled water under controlled conditions to reach 20% w/w concentration, always adding acid to water to prevent excessive heat and splashing.
🔬 Properties
The chemical formula is H₂SO₄, and at 20% concentration, the solution is less viscous and less corrosive than concentrated acid but still strongly acidic with pH around 0.3. It is a clear, colorless to slightly yellow liquid, fully miscible with water, and strongly reactive with bases, metals, and organic compounds.
🧪 Applications
Sulfuric acid 20% is widely used for pH adjustment, acidification, cleaning, and digestion of samples in analytical chemistry and pharmaceutical formulations. It is suitable for processes requiring acid catalysis and in situations where concentrated acid would be too aggressive.
⚠️ Safety
Despite being diluted, sulfuric acid 20% remains corrosive and can cause skin and eye irritation or burns. Vapors may irritate respiratory pathways. Proper PPE, including gloves, goggles, and lab coat, is necessary when handling. It should be stored in corrosion-resistant containers, away from incompatible substances like bases and organic materials.
