124. Solving a chemistry problem

Tasks 81-90. The sol of substance C is obtained by mixing dilute solutions A and B in various non-stoichiometric proportions. In electrophoresis, sol particles move towards a specific electrode.
1. Determine which of the components was present in excess.
2. Write the chemical reactions of sol formation.
3. Give the formula of micelles of the sol.
Why is it necessary to use dilute solutions in a non-stoichiometric proportion of components to obtain a sol by chemical condensation?
option A B C Direction of motion of sol particles
89 NaF SrCl2 SrF2 to cathode