The sum of oxidation states of two silver ions in [Ag(NH₃)₂] [Ag(CN)₂] complex is _____________.

Solution

Chemistry ma’am · 4 steps

Split the salt into its cation and anion first, then find silver's state inside each one.

1. Split the salt. The compound is neutral, so it is an ion pair: the complex cation [Ag(NH₃)₂]⁺ and the complex anion [Ag(CN)₂]⁻. A charge of +1 and a charge of -1 add up to zero.
2. Silver in the cation. NH₃ is a neutral ligand, so it adds 0. Then x + 2(0) = +1, which gives x = +1.
3. Silver in the anion. CN⁻ carries a charge of -1. Then y + 2(-1) = -1, which gives y = +1.

   x + y = (+1) + (+1) = +2

4. So. Both silver ions are in the +1 state, and the sum of their oxidation states is 2.

The common slip: 0. Treating CN⁻ as a neutral ligand, like NH₃, makes the silver in the anion -1 and the sum 0.

The idea to keep. For a salt made of two complex ions, first fix the charge of each ion. Then subtract the ligand charges inside each bracket: neutral ligands like NH₃ add 0, anionic ones like CN⁻ add -1.

Answer from the NTA final answer key. Solution by PrepWiser.