Sulphur

Sources: It is found as an element, in large underground beds in several countries. It is also found around the rims of volcanoes. It occurs in metal ores (lead sulphide aka galena). Sulphur compounds also occur naturally in the fossil fuels: coal, oil and natural gas.

Uses of sulphur: the manufacture of sulphuric acid (through the Contact process), vulcanising rubber, used to make drugs, pesticides, matches and paper, and some is added to cement to make sulphur concrete, which cannot be attacked by acid in walls and floors in factories.

Uses of Sulphur dioxide

-manufacture of sulphuric acid

-to bleach wool, silk and wood pulp for making paper

-it is used as a sterilising agent in making soft drinks and jam, and in drying fruit. It stops growth of bacteria and moulds.

Uses of sulphuric acid: making fertilisers such as ammonium sulphate, paints, pigments, and dyestuffs, fibres and plastics, soaps and detergent, acid in car batteries

The Contact process: sulphur → burned in air → sulphur dioxide → mixed with more air → passed over four separate beds of catalyst (pellets of Vanadium (V) oxide) at 450°C → sulphur trioxide → dissolved in concentrated sulphuric acid → thick fuming liquid called oleum → mixed carefully with water → concentrated sulphuric acid.

CONDITIONS: vanadium (V) oxide catalyst, 450°C, less that 2atm of pressure

Properties of sulphuric acid:

-Forms salts called sulphates

-When concentrated, it is a dehydrating agent, and a thick oily liquid

-It turns blue litmus red

-It is a strong acid

-normal strong acid properties (reacts with bases, low pH, high conductivity etc.)