To calculate the total ion concentration of a 0.100 M K2SO4 solution, we need to consider the dissociation of K2SO4 in water. K2SO4 dissociates into 2 K+ ions and 1 SO4^2- ion.

Total ion concentration = [K+] + [SO4^2-]

[K+] = 2 x [K2SO4] = 2 x 0.100 M = 0.200 M

[SO4^2-] = 1 x [K2SO4] = 1 x 0.100 M = 0.100 M

Total ion concentration = 0.200 M + 0.100 M = 0.300 M

Therefore, a 0.100 M solution of K2SO4 would contain the same total ion concentration as a 0.300 M solution of a 1:1 electrolyte (such as NaCl) or a 0.150 M solution of a 2:1 electrolyte (such as MgSO4).