n factor of IO3‌−and I−in the given redox reaction are 5 and 1 respectively. Therefore, IO3‌−will always react in the molar ratio 1:5 to get I2. IO3−+6H++5I−→3I2+3H2O To get 6 molar I2, multiple equation by 2 ‌2IO3−+12H++10I−→6I2+6H2O ‌‌ So, ‌x=10