Hi Ty,
Sorry for the delay in replying. I didn't know the answer to this initially but I've made some enquiries on your behalf.
From what I can gather the online experiments very much start at the stage 2 module S215. The module description gives the following information regarding the practical work (there is also an optional residential school for this module).
Practical work
As Chemistry is such a practical subject the final Practical Block introduces you to aspects of laboratory work. It starts by introducing common apparatus and techniques and health and safety aspects of working in a laboratory. There are video sequences illustrating some of the techniques and an online experiment on some techniques. Online experiments play an important role in acquainting you with the practical aspects of chemistry. During your study of chemical kinetics, you will measure the rate of a reaction using a virtual spectrometer.
The Practical Block provides further experience of experimental methods. You will be introduced to standard apparatus and techniques of the chemistry laboratory and will then undertake three online experiments.
The first uses the virtual spectrometer to measure an equilibrium constant, and the other two allow you to experience a laboratory in an immersive environment. These two experiments are a titration using a pH meter and a synthesis of a copper complex. You will select and assemble apparatus, measure out chemicals and adjust the reaction conditions. Your results will depend on your choices and so, as in real life, they will differ from those of other students.
In addition to this the module has a self assessed diagnostic quiz (as do all the science modules). The self assessment quiz will also give you an idea of the module content. I have the link below, plus a link to some appropriate taster materials related to this module.
http://www.open.ac.uk/science/main/studying-science/s215-chemistry-essential-concepts http://www.open.edu/openlearn/science-maths-technology/what-chemical-compounds-might-be-present-drinking-water/content-section-0 I hope this helps.
Iain