LUCÍA ROMERO
12. SULFUR
12.1 SULFUR
Characteristics
▪ It is a yellow solid at room temperature
▪ It has a low melting point (115 degrees)
Sources
1. It is produced during the refinement of petroleum
2. In crude oil and natural gas
3. Places like USA, Texas, Ethiopia, Australia
Uses
1) To make sulphuric acid
2) To toughen rubber, in a process called vulcanisation
USES OF SULPHURIC ACID:
I. Car batteries
II. Laboratory acids
III. Fertilisers
IV. Soaps and detergents
V. Paints and dyes
The contact process / making sulfuric acid
Sulphuric acid→ H2SO4
RAW MATERIALS:
1. Sulphur
2. Air
3. Water
STEP 1:
Roast it (the sulphur) in air, to form SULPHUR DIOXIDE
S + O2 → SO2
STEP 2:
Mix it with more air, and pass over 4 separate beds of a catalyst, to form SULPHUR TRIOXIDE
Factors needed:
1. A vanadium oxide (V2O5) catalyst
2. A temperature of 450 degrees
3. Pressure of 1-5 atmospheres
2SO2 + O2 ⇄ 2SO3
STEP 3:
Dissolve the sulfur trioxide in concentrated sulphuric acid, to form OLEUM
SO3 + conc H2SO4 → H2S2O7 (oleum)
Why don’t we put sulfur trioxide directly in water?
Because the direct combination of SO3 with water is too exothermic and forms a fine mist of acid.
STEP 4:
Dilution of oleum (we mix it carefully with water), to get CONCENTRATED SULPHURIC ACID (H2O + H2S2O7 → 2H2SO4)
12. SULFUR
12.1 SULFUR
Characteristics
▪ It is a yellow solid at room temperature
▪ It has a low melting point (115 degrees)
Sources
1. It is produced during the refinement of petroleum
2. In crude oil and natural gas
3. Places like USA, Texas, Ethiopia, Australia
Uses
1) To make sulphuric acid
2) To toughen rubber, in a process called vulcanisation
USES OF SULPHURIC ACID:
I. Car batteries
II. Laboratory acids
III. Fertilisers
IV. Soaps and detergents
V. Paints and dyes
The contact process / making sulfuric acid
Sulphuric acid→ H2SO4
RAW MATERIALS:
1. Sulphur
2. Air
3. Water
STEP 1:
Roast it (the sulphur) in air, to form SULPHUR DIOXIDE
S + O2 → SO2
STEP 2:
Mix it with more air, and pass over 4 separate beds of a catalyst, to form SULPHUR TRIOXIDE
Factors needed:
1. A vanadium oxide (V2O5) catalyst
2. A temperature of 450 degrees
3. Pressure of 1-5 atmospheres
2SO2 + O2 ⇄ 2SO3
STEP 3:
Dissolve the sulfur trioxide in concentrated sulphuric acid, to form OLEUM
SO3 + conc H2SO4 → H2S2O7 (oleum)
Why don’t we put sulfur trioxide directly in water?
Because the direct combination of SO3 with water is too exothermic and forms a fine mist of acid.
STEP 4:
Dilution of oleum (we mix it carefully with water), to get CONCENTRATED SULPHURIC ACID (H2O + H2S2O7 → 2H2SO4)
