all of them please

Calculate the corresponding water hardness of a mixture of 45ml of 0.05MCaCO&35ml of 0.1MMgCO3 ? 1. In the reaction; (I2+2S2O32S4O62+2I),12.7 g of I2 would require how many grams of Na2S2O3 for complete reaction? 2. CuSO4 reacts with KI to produce I2 as: (2Cu2++4I2CuI+I2). If 15.9g of CuSO4 react with 4.15g of KI. Which reactant will finish first? What amount of I2 will be formed (in moles and grams)