This is a draft cheat sheet. It is a work in progress and is not finished yet.
Sources of sulfur
• In it’s elemental form underground in USA, Mexico and Poland |
• Can be made from Sulfides ores |
• Bi-product of from removal of sulfur from petroleum and natural gas |
Uses of sulfur
• Making of sulphuric acid (important chemical used in many industries) |
• Used extensively in making rubber tyres more flexible- vulcanising (rubber tyre is heated with sulfur) |
Sulfur dioxide
• Made by the direct combination of sulfur with oxygen |
→ This method is the first stage of manufacture of sulphuric acid |
S + O₂ → SO₂ |
Uses of sulfur dioxide
• As a bleach in the manufacture of wood pulp for paper |
• Preservative for foods and drinks by killing bacteria |
• Sulfites are added to foods and these release sulfur dioxide in acidic conditions |
|
|
Manufacture of sulphuric acid
• Synthesized by the contact process |
→ Uses sulfur and oxygen from air |
→ Is done in three distinct conditions |
| |
Stage 1) Oxidation of sulfur |
S + O₂ → SO₂ |
Stage 2) Oxidation of SO₂ to sulfur trioxide |
Catalyst used: V₂O₅ |
2SO₂ + O₂ ⇌ 2SO₃ |
Conditions during stage 2 |
Temperature 450°C |
→ Reaction is exo so increasing temperature shits equilibrium position to the left therefore, higher the temperature, lower the yield. |
Pressure 2 atm |
→ Increase in pressure shifts equilibrium position to the right (direction of a smaller number of gaseous moles) |
Stage 3) Sulfur trioxide is absorbed into solution of sulfuric acid to produce oleum |
SO₃ + H₂SO₄ → H₂S₂O₇ |
→ Trioxide isn't absorbed into water because a fine mist of sulfuric acid will be produced and this would be difficult to produce and thus, highly dangerous |
→ Oleum is added to water to form concentrated sulfuric acid |
H₂S₂O₇ + H₂O → 2H₂SO₄ |
Properties of sulfuric acid
•It is a strong dibasic acid (two of its hydrogen atoms can be replaced by a metal) |
•Reacts in a similar way to other acids with metal carbonates, oxides, hydroxides and metals (and ammonia) |
•Concentrated sulfuric acid is corrosive and a powerful oxidizing agent |
•A very powerful dehydrating agent (very good at removing water from other substances |
Uses of sulfuric acid
DIlute |
•Used as a catalyst in many organic reactions |
•To clean the surface of metals |
Concentrated |
•Used in car batteries, making phosphate fertilizers, soaps and detergents |
•Used to make acid drain cleaners |
•Used in production of paints and dyes |
Sugar and sulfuric acid
When mixed with sugar, (C₆H₁₂O₆), concentrated H₂SO₄ will remove water molecules and leave behind carbon, producing a tower of pure carbon
|
