a$.$ What test methods would you put in place to analyse your soap noodles when you receive your stock to validate them and briefly describe each test method. $[10$ marks$]$b$.$ The formulating of soap bars has become more complex over the years due to the need to incorporate more additives to an ever$-$increasing number of soap bases. What matrix effects must be considered when developing soap formulae, bearing in mind how the combination can positively or negatively impact the end product. $[10$ marks$]$