Intermediate Topic 658 of 1102 Inorganic Chemistry
Sulfuric Acid
The most produced industrial chemical, strongly acidic, dehydrating and oxidizing when hot and concentrated.
In-depth explanation of Sulfuric Acid
Sulfuric acid, H2SO4, is a dense, oily liquid and the most widely produced industrial chemical. It is made by the contact process, in which SO2 is oxidized to SO3 over a vanadium(V) oxide catalyst at about 400 to 450 degrees C and the SO3 is absorbed in concentrated acid. It is a strong acid, and it is a powerful dehydrating agent that removes water from carbohydrates. When hot and concentrated it is also an oxidizing agent. Its major uses include fertilizers, lead-acid batteries, detergents and pigments.
Going deeper: Sulfuric Acid
Key ideas: Contact process: S burns to SO2, then 2SO2 + O2 gives 2SO3 over V2O5 at 450 C and 1 to 2 atm, delta H = -197 kJ per mol. SO3 is absorbed in 98 percent H2SO4 to give oleum H2S2O7, then diluted, because SO3 in water forms an acid mist. Concentrated acid is a dehydrating agent (sugar turns to carbon), oxidant when hot, and low volatility. Always add acid to water.
Common mistakes and connections: Students expect very high pressure for yield; moderate pressure suffices because conversion is already near 99 percent. Another mistake is claiming conc H2SO4 is a strong acid in both protons; HSO4- has pKa near 2. Dehydration differs from drying gases. It is not used to dry NH3 or H2S. Links to equilibrium, catalysts, oleum and sulfur dioxide.
Visualization of Sulfuric Acid
Contact process step 2SO2 + O2 to 2SO3 is exothermic by about 99 kJ/mol of reaction; the V2O5 catalyst lowers the barrier. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Concentrated sulfuric acid poured onto sugar removes its water and leaves a black mass of carbon.
Frequently asked questions about Sulfuric Acid
What is Sulfuric Acid?
The most produced industrial chemical, strongly acidic, dehydrating and oxidizing when hot and concentrated.
Is Sulfuric Acid a beginner, intermediate or advanced topic?
Sulfuric Acid is a intermediate topic in Inorganic Chemistry. It builds on the vocabulary of beginner topics in this area.
What should I learn before Sulfuric Acid?
Study these earlier topics in Inorganic Chemistry first: Oxides, Sulfur Allotropes, Sulfur Dioxide.
What comes after Sulfuric Acid?
The next topics in Inorganic Chemistry are Halogens and Halogen Reactivity Trend.
Can I practise Sulfuric Acid with quizzes?
Yes. The interactive lesson includes a self-check question on Sulfuric Acid, and the Inorganic Chemistry quiz draws on every topic in this area.
Where Sulfuric Acid fits in Inorganic Chemistry
Sulfuric Acid is topic 43 of 113 in Inorganic Chemistry.