Sulfur

Sources

  • Found as an element, in large underground beds

  • Found around the rims of volcanoes.

  • It occurs in metal ores e.g. lead sulphide

  • Sulphur compounds also occur naturally in the fossil fuels e.g. coal

Uses

SulfurSulfur Dioxide
As a food preserver; kills bacteriaManufacture of sulphuric acid
As a bleach in the manufacture of wood pulp for paperTo bleach wool, silk and wood pulp for making paper
In car batteries as electrolyteAs a sterilising agent in making soft drinks and jam, and in drying fruit; stops growth of bacteria and moulds.
In manufacture of sulphuric acid (through Contact process)

Contact Process

  • Sulphur is first burned in air producing sulphur dioxide

  • It is then mixed with more air and passed over four separate beds of catalyst, Vanadium (V) oxide, at 450°C to form sulphur trioxide

  • It is then dissolved in concentrated sulphuric acid forming a thick fuming liquid called oleum

  • It is then mixed carefully with water to form concentrated sulphuric acid.

  • Essential conditions:

    • Catalyst: Vanadium (V) oxide

    • Temperature: 450°C

    • Pressure: 2atm

Properties of Sulfuric Acid

  • Forms salts called sulphates

  • When concentrated, it's a dehydrating agent, and a thick oily liquid

  • It turns blue litmus red

  • It is a strong acid and has the properties of a typical strong acid: reacts with bases, low pH, high conductivity