12 Sulfur

Question 1

Equations for sulfuric acid production (Contact process)

Answer 1

S + O2 –> SO2
2SO2 + O2 <=> 2SO3
H2SO4 + SO3 –> H2S2O7
H2S2O7 + H2O –> 2H2SO4

Question 2

Sources of sulfur

Answer 2

Volcanoes; obtained from some metal ores like copper pyrites (CuFeS₂) and Blende (ZnS) and other purification processes, as all living things and fossils contain sulfur

Question 3

Contact process conditions

Answer 3

Catalyst of vanadium(V) oxide, V₂O₅
Temperature of around 450 degrees Celsius
Pressure of 2 atm

Question 4

Uses of sulfur dioxide

Answer 4

a bleach in the manufacture of wood pulp for paper
a food preservative (killing bacteria)

Question 5

Properties of sulfuric acid

Answer 5

strong acid - fully dissociates in solution to release H⁺ ions
corrosive - more concentrated is more corrosive
good electrolyte

Question 6

Uses of sulfuric acid

Answer 6

production of fertilisers; manufacture of chemicals, sulfate salts, synthetic detergents, dyes and pigments, explosives and drugs; to wash impurities out of gasoline and other refinery products; in processing metals; rayon, the electrolyte in the lead-acid storage battery, is made with sulfuric acid

Question 7

Contact process method

Answer 7

1. burn sulfur in air
2. sulfur dioxide converted into sulfur trioxide under certain conditions
3. sulfur trioxide is reacted with water