According to IUPAC nomenclature sodium nitroprusside is named as

Options

A. sodium pentacyanon1trosyl ferrate (II)
B. sod1urr1p entacyanonitrosyl ferrate (Ill)
C. sodium nitrofemcyanide
D. sodium nitroferrocyanide

Explanation

To name sodium nitroprusside according to IUPAC nomenclature, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Formula**:
The formula for sodium nitroprusside is Na2[Fe(CN)5(NO)].

2. **Ionization**:
When sodium nitroprusside dissociates in solution, it yields:
- 2 Na⁺ ions
- The complex ion [Fe(CN)5(NO)]²⁻.

3. **Determine the Oxidation State of Iron**:
Let the oxidation state of iron (Fe) be x. The ligands CN⁻ (cyano) contribute -1 charge each, and there are 5 of them, contributing a total of -5. The NO (nitrosyl) ligand is neutral (0 charge). The overall charge of the complex ion is -2. Therefore, we can set up the equation:
\[ x + (-5) + 0 = -2 \]
Solving for x gives:
\[ x - 5 = -2 \implies x = +3 \]
Thus, iron is in the +3 oxidation state.

4. **Naming the Ligands**:
- The ligand CN⁻ is called "cyano."
- The ligand NO is called "nitrosyl."

5. **Construct the Name**:
According to IUPAC rules, we start with the ligands in alphabetical order, followed by the metal. Since there are five cyano ligands, we use the prefix "penta-":
- "pentacyano"
- "nitrosyl"
- "iron" (with the suffix "-ate" because the complex has a negative charge, thus it becomes "ferrate").

6. **Include the Oxidation State**:
Since iron is in the +3 oxidation state, we denote this in the name as "ferrate(III)."

7. **Final Name**:
Combining all parts, we get the full IUPAC name:
**Sodium pentacyanonitrosylferrate(III)**.

### Final Answer:
The IUPAC name of sodium nitroprusside is **Sodium pentacyanonitrosylferrate(III)**.