2Cu2++4I−→Cu2I2+I2 I2+S2O32−→2I−+S4O62− Milliequivalents of hypo solution =0.02×20=0.4 Milliequivalents of Cu2+ in 10‌mL solution = Milliequivalents of I2= Milliequivalents of hypo =0.4 Millimoles of Cu2+ ions in 10‌mL=0.4 Molarity of Cu2+ ions =‌