Page 25 - Curriculum Visions Dynamic Book

Poisonous hydrogen sulphide
Hydrogen sulphide is a highly poisonous gas, which, because it has no colour, can only be detected by
its smell. In fact, all the gases of sulphur (SOX) are poisonous and most have unpleasant, choking odours.
pyrite: “mineral of fire”. This name comes from the fact that pyrite (iron sulphide) will give off sparks if struck with a stone.
reducing agent: a substance that gives electrons to another substance. Sulphur dioxide is a reducing agent, used for bleaching bread.
Hydrogen sulphide smells like rotten eggs
Hydrogen sulphide is present in natural gas and is
also produced during the decay of dead material in
the absence of water. This is one reason that some decaying remains and stagnant waters have a bad smell.
Hydrogen sulphide smells like rotten eggs. The odour occurs when the proteins of dead tissue that contain sulphur begin to decompose.
 Nickel sulphide.
 Cadmium sulphide.
Tarnishing
Hydrogen sulphide is the polluting gas that reacts with silver in the atmosphere to produce black tarnishing (silver sulphide) on silverware.
Also...
Many fossil fuels contain sulphides, which are soluble in water. As water seeps into mine workings, it dissolves the sulphides and may subsequently find its way into groundwater or streams, where it can cause widespread and serious pollution. This is why the water pumped from active mines has to be carefully treated before being discharged.
EQUATION: Removing sulphur-containing impurities such as hydrogen sulphide from petroleum with sodium hydroxide
Hydrogen sulphide + sodium hydroxide ➪ sodium sulphide + water H2S(g) + 2NaOH(aq) ➪ Na2S(s) + 2H2O(l)
Because SO gases quickly paralyse the nerves in X
the nose, their smell soon appears to go away. This is very dangerous effect because it encourages people to remain in contact with the gas, rather than move away.
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