Sulfuric acid has the chemical formula H2SO4. It contains two hydrogen atoms, one atom of sulfur, and four oxygen atoms.
Appearance: Sulfuric acid is a colorless, oily liquid. It is usually yellow in concentrated form, if not impure.
Smell: It is mostly odorless but may have a faint, acrid smell due to the strongly acidic nature it possesses.
Density: Concentrated sulfuric acid is heavy at 1.84 g/cm³ at 25°C. Its density rises with concentration.
Boiling point: Sulfuric acid has a fairly high boiling point, at about 337°C or 639°F.
Melting point: The melting point of sulfuric acid is approximately 10°C or 50°F. Because it possesses a very high melting point, it's always in liquid form.
Solubility: It has been remarked above that sulphuric acid is highly water-soluble. Its reaction with the water is exothermic, which means it releases temperature while reacting with water. In many applications, it is diluted by water, and in case it needs to be added to water, it has to be done very gently as it can lead to overflow and excessive heating of the solution.
Viscosity: It is a highly viscous liquid. Its viscosity decreases with an increase in temperature.
Hygroscopicity: Sulfuric acid is hygroscopic and can absorb moisture from the air, causing its dilution and generation of sulfuric acid mist.
Reactivity with water: The mixture of sulfuric acid with water gives off a substantial amount of heat, and the reaction is very exothermic. The acid must be added to cold water slowly to keep the heat within manageable limits and avoid dangerous spattering.
Strong acidic behavior: Sulfuric acid is also a strong diprotic acid, which in turn means it can donate two protons in aqueous solutions. Dissociation in water can be represented by
Dehydrating agent: Sulfuric acid is a very good dehydrating agent. This is because it removes water from most carbohydrates. For example, it dehydrates sugar - sucrose, into carbon and water.
Oxidizing agent: Concentric sulfuric acid is an oxidizer. It will directly oxidize metals like copper and silver, and it reacts with reducing agents such as hydrogen sulfide (H₂S) or sulfur dioxide (SO₂).
Reaction with bases: Sulfuric acid is also well known to react with bases in the formation of salts and water. For example, it reacts with sodium hydroxide, NaOH, to form a sodium sulfate, Na₂SO₄, and water, H₂O.
H2SO4+2NaOH→Na2SO4+2H2O
Reaction with metals: Sulfuric acid reacts with a wide range of metals including zinc and iron; the products are metal sulfates and hydrogen gas.
Zn+H2SO4→ZnSO4+H2
Heat of dissolution: Since sulfuric acid ionizes when mixed with water, this provides a highly exothermic dissolution process and may result in the mixture heating up very well. This mixture could cause splashing if handled strongly.
Complexation: Sulfuric acid tends to form complexes with some substances. For example, sulfuric acid can form complex salts with metals such as copper and iron, which are normally used in various procedures of a chemical nature.
Phosphate fertilizers: Sulfuric acid is used in the manufacture of phosphoric acid, which in turn is then used in the manufacture of phosphate fertilizers such as superphosphate and ammonium phosphate.
Sulfuric acid fertilizers: It is also directly used in the production of fertilizers, for example, ammonium sulfate.
Sulfuric acid as an alkylation catalyst: As a catalyst in alkylation, it is utilized in the process that produces high-octane components of gasoline by the use of alkenes and alkanes.
Desulfurization: This helps in removing sulfur impurities from petroleum products to reduce pollution.
Chemical production: Sulfuric acid is used for the production of hydrochloric acid, nitric acid, and synthetic detergents among many other chemicals.
Cleaner agent: It is a chemical used in cleaning metal surfaces that are involved in different stages of various industries.
Pickling: Sulfuric acid is utilized in pickling for the removal of oxide layers and impurities from the surfaces of metals like steel and iron among others, before their processing or coating.
Electrolytes in batteries: This is an important constituent in lead-acid batteries, where it acts as the electrolyte.
Dyeing and printing: Sulfuric acid is used in dyeing and printing textiles.
Paper manufacturing: The use of sulfuric acid is found in the paper and pulp industry, mainly in the sulfate or Kraft process.
pH adjustment: Used for pH adjustment in water treatment for neutralizing alkaline substances to purify the water.
Reagent: Sulfuric acid is used as a reagent in many chemical analyses and laboratory experiments.
Manufacturing: Used in the manufacture of soaps and other detergents, including industrial cleaners.
pH control: Sulfuric acid is used in some processes in food processing as an acidifying agent.
Thus, with these properties, the uses of sulfuric acid become very wide in various industries: in the production of fertilizers, petroleum refining, and chemical manufacturing. On the other hand, because of its corrosive nature, great caution must be taken in handling it with appropriate safety equipment and protocols.