What should we use in soap making process:- a) potassium hydroxide
b) sodium hydroxide (lye)

Explain why it should be used

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).