Sulfuric acid
Sulfuric acid, also spelled sulphuric acid, is a strong, corrosive acid and reducing agent and is one of the most important chemicals in the chemical industry. Personal protective gear should be worn when using sulfuric acid.
properties and uses of sulfuric acid
Sulfuric acid is a strong acid, an oxidizing agent and a dehydrating agent.
Because it has a high boiling point (3330C), it can be used to make other more volatile acids using the appropriate acid salt. Nitric acid can be made by reacting sulfuric acid with sodium nitrate, NaNO3. Distilling the resultant nitric acid (BP=86C) drives the reaction towards completion.
- NaNO3 + H2SO4 → HNO3 + NaHSO4
synthesis of sulfuric acid
Sulfuric acid is made be reacting sulfur trioxide with water in an exothermic reaction.
- SO3(g) + H2O(l) → H2SO4(l) + 130 kJ mole-1
In the commercial production of sulfuric acid, the contact process or the lead-chamber process is used. In the contact method, sulfur dioxide is catalytically converted to sulfur trioxide by surface chemistry with fine platinum powder or, more recently, vanadium pentoxide (V2O5). The resulting sulfur trioxide gas is bubbled through sulfuric acid and the addition of water at the correct rate yields 98% acid pulled out.
The lead-chamber process uses sulfur dioxide, oxygen, nitric acid and water vapor are introduced into a lead-lined chamber. White crystals of nitrosulfuric acid (nitronium sulfate), NOHSO4, are formed. The introduction of steam then converts the nitrosulfuric acid to sulfuric acid liberates nitrogen oxides, which can be reused in the first step of the reaction.
- 1) 2SO2 + NO + NO2 + O2 + H2O → 2NOHSO4
- 2) 2NOHSO4 + H2O → 2H2SO4 + NO + NO2