In this I/GCSE chemistry blog post, we will be looking at properties of sulphur dioxide, let's go!
SULPHUR DIOXIDE, SO2
- This is the most important oxide of sulphur, and is formed when sulphur burns.
- In industry it is obtained when sulphide metal ores such as zinc sulphide are roasted in air.
- Chemical properties of sulphur dioxide:
- It's a reducing agent - will remove oxygen from other compounds.
- It kills bacteria - used as a food preservative.
A chemical test for sulphur dioxide
- A solution of potassium dichromate(VI) is acidified with dilute sulphuric acid.
- This mixture is bright orange.
- A piece of filter paper dipped into this and exposed to sulphur dioxide gas will turn green due to the formation of chromium sulphate.
Another chemical test for sulphur dioxide
- A solution of potassium manganate(VII) is acidified with sulphuric acid.
- This is deep purple.
A paper dipped in this will be decolourised by sulphur dioxide gas.
SULPHITES
- Sulphites have the general formula M2SO3 if M is a metal with a valency of one, or MSO3 if it has a valency of two. The sulphite ion is SO3^2- .
- Sulphuric acid is manufactured by the contact process. The main stages are the reaction of sulphur dioxide with oxygen to form sulphur trioxide .
- The product of this reaction is then reacted with sulphuric acid to form oleum. This can then be diluted down to form sulphuric acid.
That is all!
References:
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.researchgate.net%2Ffigure%2FStructural-formula-of-sodium-sulfite-anhydrous_fig1_301547928&psig=AOvVaw0u2D2WJx6LShH5U0lWWnSI&ust=1628944241444000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCJjc2qmArvICFQAAAAAdAAAAABAD
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.askiitians.com%2Fiit-jee-s-and-p-block-elements%2Fsulphur-dioxide%2F&psig=AOvVaw1ShOfFiYqBjca67u1HE3PY&ust=1628944373084000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCPimue6ArvICFQAAAAAdAAAAABAU
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