Lesson-specific diagram for Ion concentrations when solutions are mixed. It visualizes the reasoning sequence tied to $n_i=cV,\quad c_{i,f}=n_{i,total}/V_{total}$. Text alternative: Mixed-solution ion concentrations require stoichiometric dissociation, mole bookkeeping, and a clearly stated total-volume assumption. Choose a representation that matches the chemical scale and evidence; do not infer more precision or mechanism than the data support.