Before commencing Module G(2023), you should be very confident working with the material contained in Modules A(0000) S.I., B(2019), C(2020), D(support), E(2021) & F(2022).  However, one can begin tackling Module H(2024) Stoichiometry without considering what is contained here in G(2023).  For the majority, this is usually the most efficacious treatment.