3. The stepwise stability constant, K at 25 C in an aqueous solution for the formation of copper and nickel complexes are shown below. [M(H2O) (en)? [M(H2O)2(en)2] [M(en)]* Cu 3x 100 1 x 109 0.1 Ni 1x 1090 1 x 1070 1 x 1070 (a) Express the chemical equations that are characterised by the stepwise stability constants for the three complexes formed by nickel (6 marks) (b) Explain the significant difference in the K value of [M(en)3p+ for copper and nickel (2 marks) (c) Demonstrate what will happen if the en changed to NHa