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What it is. This sulfuric acid solution is a 0.1 N (0.05 M) volumetric standard, supplied in a 1-gallon size. It is a clear, colorless acid titrant for alkalinity, ammonia, Kjeldahl nitrogen, and routine titrations of bases.
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Normality versus molarity. Sulfuric acid releases two hydrogen ions per molecule, so 0.1 N equals 0.05 M. Each liter contains about 4.904 g of H2SO4, and each milliliter neutralizes 0.1 milliequivalent of base (calculated).
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What each milliliter titrates. One milliliter of 0.1 N sulfuric acid neutralizes 4.000 mg of sodium hydroxide, 1.703 mg of ammonia, or the ammonia from 1.401 mg of nitrogen, and corresponds to 5.004 mg of alkalinity as calcium carbonate (calculated).
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Kjeldahl nitrogen. In Kjeldahl methods, distilled ammonia is trapped in boric acid and titrated directly with standard acid, or trapped in excess standard acid and back-titrated. With 0.1 N acid, each milliliter corresponds to 1.401 mg of nitrogen.
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Alkalinity titrations. In water analysis, alkalinity is titrated with standard sulfuric acid to endpoints near pH 8.3 and 4.5. Sulfuric acid is common in standard alkalinity methods because it is non-volatile and stable.
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Stable standard. Unlike hydrochloric acid, sulfuric acid does not volatilize from solution, so 0.1 N standards keep their strength well. Standardize against sodium carbonate or standardized sodium hydroxide before critical work.
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Gallon size for routine testing. The 1 gallon size supports water, food, and environmental labs that titrate daily, providing one consistent lot over an extended period.
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Standardization. Standardize 0.1 N sulfuric acid against dried primary standard sodium carbonate with methyl orange, boiling near the endpoint to expel carbon dioxide, or against standardized sodium hydroxide with phenolphthalein. Re-standardize periodically for regulated work.
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Calculating results. Base or analyte content equals the titrant volume multiplied by the standardized normality and the analyte's milliequivalent weight, minus any reagent blank. Each milliliter of 0.1 N acid equals 0.1 milliequivalent.
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Related products. For stronger acid, see Lab Pro's Sulfuric Acid 0.5 N Solution, 1 L. For alkalinity endpoints, use Methyl Orange Indicator, 0.1% (w/v) Aqueous or Phenolphthalein Indicator 1% in IPA (1 Pint, 20 L).
Technical Specifications
| Chemical Name |
Sulfuric acid, aqueous solution |
| CAS Numbers |
7664-93-9 (sulfuric acid); 7732-18-5 (water) |
| EC Number (H2SO4) |
231-639-5 |
| Synonyms |
Oil of vitriol (concentrated), battery acid (dilute), H2SO4 solution |
| Formula (active) |
H2SO4 |
| Molecular Weight (active) |
98.08 g/mol |
| Equivalent Weight |
49.04 (diprotic; normal = 2 x molar) |
| Concentration |
0.1 N (0.05 M) |
| H2SO4 Content |
About 4.904 g/L (calculated) |
| Titration Equivalence |
1.00 mL = 4.000 mg NaOH; 1.703 mg NH3; 1.401 mg N; 5.004 mg CaCO3 (calculated) |
| pH (0.1 N, reference) |
About 1.2 |
| Appearance |
Clear, colorless liquid |
| Physical State |
Liquid, aqueous solution |
| Hazard Profile |
Skin and eye irritant at this strength |
| Exposure Limit (mist) |
OSHA PEL and NIOSH REL: 1 mg/m³ TWA |
| Package Size |
1 gallon |
Applications / Common Uses
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Alkalinity: Titrates water alkalinity to pH 8.3 and 4.5.
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Kjeldahl nitrogen: Titrates distilled ammonia.
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Ammonia determination: Measures ammonia in water and wastewater.
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Base titration: Titrates bases in QC labs.
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NaOH verification: Cross-checks standard sodium hydroxide.
Storage, Handling & Shipping
Store tightly closed in a corrosives cabinet away from bases, reactive metals, organic materials, and water-reactive substances. When diluting, always add acid slowly to water, never water to acid, since dilution releases heat.
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Incompatible materials: Bases, reactive metals (release hydrogen), organic materials, oxidizers and reducers, and cyanides or sulfides.
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Exposure limit (sulfuric acid mist): OSHA PEL and NIOSH REL: 1 mg/m³ TWA.
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Spill response: Contain and neutralize with sodium bicarbonate or an acid spill kit, then rinse with water.
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First aid: Skin or eyes: flush with water for at least 15 minutes and seek medical attention.
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GHS signal word: Danger or Warning depending on concentration.
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DOT / shipping: UN2796, Sulfuric acid, Class 8.
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