IUPAC name for `K[Ag(CN)_2]` is

Options

A. (a) potassium argentocyanide
B. (b) potassium silver cyanide
C. (c) potassium dicyanidoargentate (I)
D. (d) potassium dicyanidosilver (II)

Explanation

To determine the IUPAC name for the complex ion \( K[Ag(CN)_2] \), we will follow the systematic naming rules for coordination compounds. Here’s the step-by-step solution:

### Step 1: Identify the components of the complex
The complex consists of:
- A cation: \( K^+ \) (potassium)
- A coordination complex: \( [Ag(CN)_2]^- \)

### Step 2: Identify the ligands
The ligand in this complex is \( CN^- \), which is known as cyanide. Since there are two cyanide ligands, we will use the prefix "di" to indicate the number of ligands.

### Step 3: Name the ligands
The name of the cyanide ligand is "cyanido" or "sinido". Since we have two cyanide ligands, we will use "dicyanido".

### Step 4: Identify the central metal atom
The central metal atom in the coordination complex is silver (Ag).

### Step 5: Determine the oxidation state of the metal
In the complex \( [Ag(CN)_2]^- \):
- Each \( CN^- \) ligand has a charge of -1, and there are two of them, contributing a total charge of -2.
- The overall charge of the complex is -1.
- Let the oxidation state of silver be \( x \). Therefore, we can set up the equation:
\[ x + 2(-1) = -1 \implies x - 2 = -1 \implies x = +1 \]
So, silver is in the +1 oxidation state.

### Step 6: Name the metal with its oxidation state
When naming the metal in a negative complex, we use the suffix "-ate". Therefore, silver becomes "argentate" when in the complex form. Since silver is in the +1 oxidation state, we denote it as "argentate(I)".

### Step 7: Combine the names
The full name of the complex ion is "dicyanidoargentate(I)".

### Step 8: Combine with the cation
Finally, we combine the name of the cation \( K^+ \) with the name of the complex. We name the cation first followed by the name of the complex ion in parentheses. Therefore, the complete IUPAC name is:
\[ \text{Potassium dicyanidoargentate(I)} \]

### Final Answer
**The IUPAC name for \( K[Ag(CN)_2] \) is Potassium dicyanidoargentate(I).**