Sulphur

What is Sulphur?

Sulphur is a yellow non metallic element. It is insoluble in water. Doesn't conduct electricity.

What is Sulphur dissolved in?

Methylbenzene

What is Sulphur mainly used for?

To create sulfuric acid.

What are other uses of Sulphur?

To volcanize rubber. To manufacture matches, fireworks, and fungicides.

What is an allotrope?

Allotropes are the different structural forms of an element in the same physical state.

What are the allotropes of Sulphur?

Monoclinic and Rhombic Sulphur

What is the meaning of transition temperature?

The temperature boundary at which one allotropic form of an element is converted into another allotropic form. The transition temperature for sulfur is 96°C.

What is Monoclinic Sulphur?

Formed when Sulphur in methylbenzene is heated and allowed to cool. Monoclinic Sulphur crystals are produced. The temperature is above 96°C .

What is Rhombic Sulphur?

Formed when the temperature of Monoclinic Sulphur crystals fall under 96°C.

What is the process of extracting sulfur from beds? Explain.

The Frasch process- superheated water at 170°C and hot compressed air are forced through underground pipes, pushing water and molten sulfur to the surface. Sulphur is insoluable in water causing the Sulphuer to be pure.

What is the process by which sulfuric acid is produced?

The Contact Process

What is the first part of the Contact Process?

S + O₂ -> SO₂ Impurities are removed from the Sulphur Dioxide gas and is heated to 450°C.

What is the second part of the Contact Process?

2SO₂ + O₂ ⇌ 2SO₃ ∆= - 197kJ mol⁻¹ Clean 450°C Sulphur dioxide come in contact with the catalyst Vanadium Oxide (V₂O₅) to catalyze the reaction between Sulphur Dioxide and Oxygen to produce Sulphur Trioxide.

What is the third part of the Contact Process?

SO₃ + H₂O -> H₂SO₄ The Sulphur Trioxide is added directly to water to form sulfuric acid. This reaction is extremely violent, and produces a thick mist that is difficult to deal with (it is not usually used).

What is meant by the term catalyst?

a substance which can alter the rate of a reaction without being chemically changed itself.

What is the alternative to the third part of the Contact Process?

SO₃ + H₂SO₄ -> H₂S₂O₇ (Oleum) Oleum is then added to water to produce sulfuric acid of the right concentration. H₂S₂O₇ + H₂O -> 2H₂SO₄

What are sources of sulfuric acid?

Fossil fuels, Sulphur beds, volcanic areas of the world, and metal ores.

What are some lab safety rules when dealing with sulfuric acid?

Wearing a mask to protect yourself from the choking scent, Adding acid to water, and not water to acid as it can be dangerous.

What are the two gasses contributing to acid rain?

Sulphur dioxide and Nitrogen dioxide

What are the main sources of Sulphur dioxide?

Electric power stations, burning fossil fuels.

What are the main sources of Nitrogen dioxide?

Fossil fuels, coals, oil, gas, exhaust from motor vehicles, etc.

Explain the formation of Sulphur dioxide.

Formed when sulfur or substances containing sulfur are burned in oxyen.

Explain the formation of Nitrogen Oxide.

Formed during combustion reactions in the atmosphere, when oxygen combines with nitrogen.

What is the formula for sulfurous acid?

Sulfur dioxide + water ⇄ sulfurous acid SO2 (g) + H2O(l) ⇄ H2SO3

What is a dehydrating agent?

Dehydrating agent is something that takes water out of substances.

Why is dilute sulfuric acid still considered a strong acid?

Because dilute sulfuric acid will still completely dissociate in water.

What are the physical changes seen when concentrated sulfur reacts with sugar?

An exothermic reaction would occur which would cause the carbon to solidify into a black solid (carbon) and water vapor is released.

What are the physical changes seen when concentrated sulfur reacts Hydrated copper sulphate crystals?

The concentrated sulfuric acid would react as a dehydrating agent and slowly turn the hydrated copper sulphate crystals from blue to white, leaving anhydrous copper sulphate.

What is the test for sulphates?

\-add dilute HCl acid

\-add barium chloride

\-forms a white precipitate of Barium Sulphate, if sulphate ions are present