Lab tests, results and sulphuric acid

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Slide 11

Thermal decomposition

A “thermal decomposition” reaction occurs when a compound breaks down (“decomposition”) through the action of heat.

Practical work:

Perform a thermal decomposition reaction on each of these compounds and state:

The colour changes you observed

The reaction that happened

Slide 12

Sulphuric acid

Sulphuric acid has many important uses – car batteries, detergents, fertilisers etc.

How sulphuric acid is made:

Step 1: Burn sulphur in air:

Step 2: Pass the sulphur dioxide over a vanadium oxide catalyst at 450OC:

Step 3: Dissolve the sulphur trioxide in sulphuric acid:

Step 4: Add water to the oleum:

Slide 13

Sulphuric acid

Step 2 in the manufacture of sulphuric acid is an example of a reversible reaction:

What would happen if the temperature was decreased?

Solution – use 450OC as a compromise

The reaction would favour the production of sulphur trioxide BUT the reaction would happen at a slower rate.