
Major Industrial Laboratory and Commercial Applications of Sulfuric Acid
Its molecular mass (or molar mass) is 98.08 g/mol and its molecular formula is H2SO4. The sulphur atom and two oxygen atom present in the sulphuric acid are bonded to each other via means of double bonds while the two hydrogen and two remaining oxygen atoms are present in the form of hydroxyl groups and linked to the central sulphur atom via means of single bonds. Its structure may be represented in the following manners:
FAQs on Uses of Sulfuric Acid and Their Industrial Importance
1. What are the main uses of sulfuric acid?
The main uses of sulfuric acid (H2SO4) include fertilizer production, petroleum refining, battery manufacture, and chemical synthesis. It is one of the most important industrial chemicals worldwide.
- Fertilizer production: Used to manufacture phosphoric acid and fertilizers like ammonium sulfate.
- Lead–acid batteries: Acts as the electrolyte in car batteries.
- Petroleum refining: Removes impurities from fuels.
- Chemical manufacturing: Used to produce detergents, dyes, explosives, and synthetic fibers.
- Metal processing: Used in pickling to clean metal surfaces.
2. Why is sulfuric acid used in fertilizer production?
Sulfuric acid is used in fertilizer production because it reacts with phosphate rock to produce phosphoric acid (H3PO4), a key raw material for phosphate fertilizers. The reaction is:
Ca3(PO4)2(s) + 3H2SO4(aq) → 2H3PO4(aq) + 3CaSO4(s)
- Phosphoric acid is then used to make fertilizers like superphosphate and ammonium phosphate.
- It also forms ammonium sulfate ((NH4)2SO4), an important nitrogen fertilizer.
3. How is sulfuric acid used in lead–acid batteries?
Sulfuric acid is used in lead–acid batteries as the electrolyte that enables the electrochemical reaction between lead and lead dioxide. During discharge, the overall reaction is:
Pb(s) + PbO2(s) + 2H2SO4(aq) → 2PbSO4(s) + 2H2O(l)
- Both electrodes convert to lead(II) sulfate (PbSO4).
- Sulfuric acid concentration decreases as water forms.
- On charging, the reaction reverses.
4. What is the role of sulfuric acid in petroleum refining?
In petroleum refining, sulfuric acid is used to remove impurities and in processes like alkylation to improve fuel quality. It acts as a strong acid catalyst.
- Removes unsaturated hydrocarbons and impurities.
- Used in alkylation to produce high-octane gasoline components.
- Helps improve fuel stability and combustion efficiency.
5. How is sulfuric acid used in metal processing?
Sulfuric acid is used in metal processing for pickling, which removes rust and oxide layers from metal surfaces. For example, iron(III) oxide reacts with sulfuric acid as follows:
Fe2O3(s) + 3H2SO4(aq) → Fe2(SO4)3(aq) + 3H2O(l)
- Cleans steel before galvanizing or electroplating.
- Improves adhesion of coatings.
- Removes corrosion products effectively.
6. Why is sulfuric acid called a dehydrating agent?
Sulfuric acid is called a dehydrating agent because it removes water molecules from substances due to its strong affinity for water. A classic example is its reaction with sugar (sucrose, C12H22O11):
C12H22O11(s) → 12C(s) + 11H2O(l) (in the presence of concentrated H2SO4).
- The acid absorbs the produced water.
- Leaves behind black carbon.
- Demonstrates its strong dehydrating property.
7. How is sulfuric acid used in the manufacture of chemicals?
Sulfuric acid is used in the manufacture of many chemicals as a reactant, catalyst, or dehydrating agent. It is involved in producing:
- Nitric acid (HNO3): By reacting with sodium nitrate:
NaNO3(s) + H2SO4(l) → NaHSO4(s) + HNO3(g) - Detergents and dyes: Used in sulfonation reactions.
- Explosives: Such as nitroglycerin and TNT (as part of nitration mixtures).
8. What is the importance of sulfuric acid in laboratory reactions?
Sulfuric acid is important in laboratory reactions as a strong acid, catalyst, and drying agent. It is commonly used for:
- Acid–base reactions: Neutralization with bases, e.g.,
H2SO4(aq) + 2NaOH(aq) → Na2SO4(aq) + 2H2O(l) - Drying gases: Concentrated H2SO4 absorbs moisture.
- Catalysis: Used in esterification reactions.
9. Can sulfuric acid be used in making detergents and soaps?
Yes, sulfuric acid is used in making detergents through sulfonation reactions of organic compounds. It helps introduce the sulfonic acid group (–SO3H) into hydrocarbons.
- Produces alkylbenzene sulfonates, key detergent ingredients.
- Improves cleaning efficiency by forming water-soluble salts.
- Enhances surfactant properties.
10. Why is sulfuric acid considered an important industrial chemical?
Sulfuric acid is considered an important industrial chemical because its production volume reflects a nation’s level of industrial development. It is widely used in:
- Fertilizer manufacturing
- Petroleum refining
- Metal processing
- Battery production
- Chemical synthesis





















