Sulfur

Question 1

Name some sources of sulfur

Answer 1

• Found uncombined with metals in ores such as
  + Zinc blende (ZnS) aka zinc sulfide
  + Galena (PbS) aka lead sulfide
• Found in natural gas: hydrogen sulfide (H2S)
• Sulfur dioxide
  + A colourless poisonous gas (burning fossil fuels)
  S + O2 => SO2
  + Can be made by roasting ores
  2ZnS + 3O2 => 2ZNO + 2SO2

Question 2

Name the main use of sulfur in the manufacture

of sulfuric acid

Answer 2

Sulfuric acid is used for:

• Dtergents
• Cleaning metals
• Paints and dyes
• Plastics
• Phosphate fertilisers

Question 3

Name the uses of sulfur dioxide

Answer 3

• As a bleach:
  + During the manufacture of paper from wood
  + Materials: silk, wool and straw
• Preserve food and drinks by killing bacteria b/c it is an oxidising agent
  SO3 + 2H => SO2 + H20

Question 4

Describe the manufacture of sulfuric
acid by the Contact process, including
essential conditions

Answer 4

• Sulphur burns in a furnace w/ air: S + O2 =>SO2
• Cooled and reacted with excess air in a converter - contains 4 layers of a catalyst: vanadium oxide to form sulfur trioxide (temp: 450, press: 1 atm)
• Sulfur trioxide reacts (endothermic) w/ water to form sulfuric acid in a mixture of 98% sulfuric acid and 2% water
  + SO3 +H20 => H2S04

Question 5

Describe the properties of dilute sulfuric

acid as a typical acid

Answer 5

• Has a low pH

- Donate H+ ions (2 hydrogen ions that can react) => dibasic acid