How the work of Goldsmiths pollutes air and water?
The work of Goldsmiths pollutes air and water. Copper is mixed as an alloy in gold jewellery. When this jewellery is melted by immersing it in concentrated nitric acid and extracting the alloy, copper reacts with nitric acid to produce blue-green cupric nitrate and brown nitrogen dioxide.
Cu + 4HNO3 = Cu(NO3)2 + 2NO2 ↑ + 2H2O
The nitrogen dioxide (NO2) produced enters the atmosphere causing pollution. Excess NO2 mixed with the atmosphere irritates the eyes, reducing the O2-carrying capacity of the blood. Inhalation of large amounts of NO2 causes pulmonary haemorrhage.
The resulting cupric nitrate [Cu(NO3)2] is toxic. Drains from goldsmith shops pollute the water in ponds or nearby water bodies. Damage to fish and algal plants in water bodies.
Remedial Measures to Prevent Pollution
The work of Goldsmiths pollutes air and water. But there are some remedial measures that can prevent pollution. Gold needs to be melted in a special chamber within the goldsmith’s shop. A tall chimney should be provided to remove NO2 from the chamber. This will reduce the pollution in the local area. The resulting cupric nitrate solution should be retained in a container. Later it can be supplied to the various needs of the chemical industry.