Complex a: <span>tetrachlorocuprate(i) In present complex chlorine is negatively charged ligand (-1) and oxidation state of copper is +1. Therefore, total charge on complex = 4(-1) + 1 = -3
Complex b: </span><span>pentaamminechlorocobalt(iii) In present complex, ammine is a neutral ligand (charge = 0), chlorine is negatively charged ligand (charge = -1) and oxidation state of Co is +3. Therefore, total charge on complex is 5(0) + (-1) + (+3) = +2
</span><span>Complex c: diaquadichloroethylenediaminecobalt(iii) </span>In present complex, aqua is a neutral ligand (charge = 0), chlorine is a negatively charged ligand (charge = -1), ethylenediamine is a neutral ligand (charge = 0) and oxidation state of cobalt is +3. Therefore, total charge on complex is 2(0) + 2(-1) + 2(0) + 3 = +1.
This is a double displacement reaction, C goes with Cl in the products side and O2 goes with H. All that is left is to balance the equation, making sure each side has equal amounts of atoms.