Free Unit 4 Chemistry Resources

Redox Titrations


Redox Titrations – 1

Redox Titrations – 2


Redox Titrations – Topic Test 1

Redox Titrations – Topic Test 2


Determination of the Alcohol Content of Wine

Determination of the Iron (II) Content in Lawn Fertiliser by Redox Titration

Determination of Vitamin C Content in Tablets

The Concentration of Vitamin C in Various Substances Through Redox Titration



High Performance Liquid Chromatography


Order of Elution of Sample Components


Dynamic Science – Chromatography


HPLC Concept Test

HPLC – Test 2


Determination of Caffeine in Soda

Determination of the Caffeine Content in Soft Drinks

Determination of the Caffeine Content in Commercial Tea Samples

Quantitative Analysis of Caffeine

Mixed Instrumental Techniques

Note: You may need the molecular weight of a compound in order to solve some questions.

Simply read the m/z value for the decently sized peak on the right hand side of the spectrum. In the below example, the answer is 32. Ignore tiny peaks like the one at m/z 33. Sometimes, you will get the answer wrong – but you will only be 1-2 amu from the true value. That should be enough information for you to solve these questions.