Which of the following name is impossible :

Options

A. Potassium tetrafluoridoxido chromate (VI)
B. Barium tetrafluoridochromate (II)
C. Dichlorobis (urea) copper (II)
D. All the impossible

Explanation

To determine which of the given names is impossible, we will analyze each option step by step, focusing on the oxidation states and the overall charge balance in the complexes.

### Step 1: Analyze Option A - Potassium Tetrafluoridophus
1. **Identify the components**: The name suggests a complex with potassium (K) as the cation and a complex anion involving chromium (Cr) with four fluoride ions (F) and one oxide ion (O).
2. **Determine oxidation states**:
- Potassium (K) is a group 1 element, so its oxidation state is +1.
- Each fluoride ion (F) has an oxidation state of -1, and there are four fluoride ions: \(4 \times (-1) = -4\).
- The oxide ion (O) has an oxidation state of -2.
3. **Calculate the total oxidation state of the complex**:
- The total from fluoride and oxide: \(-4 + (-2) = -6\).
- For the complex to be neutral, the oxidation state of chromium must balance this out. Therefore, the oxidation state of chromium must be +6.
4. **Check overall charge**:
- The total charge from the complex is -6, and with potassium's +1, the overall charge becomes -5. This indicates that the complex cannot exist as a neutral compound, making this name impossible.

### Step 2: Analyze Option B - Barium Tetrafluoridophus
1. **Identify the components**: The name suggests barium (Ba) as the cation and a complex anion involving chromium with four fluoride ions.
2. **Determine oxidation states**:
- Barium (Ba) is a group 2 element, so its oxidation state is +2.
- Each fluoride ion (F) has an oxidation state of -1, and there are four fluoride ions: \(4 \times (-1) = -4\).
3. **Calculate the total oxidation state of the complex**:
- The total from fluoride is -4. For the complex to be neutral, the oxidation state of chromium must be +2.
4. **Check overall charge**:
- The total charge from the complex is -4, and with barium's +2, the overall charge becomes -2. This indicates that the complex can exist as a neutral compound, making this name possible.

### Step 3: Analyze Option C - Dichlorobisuria Copper(II)
1. **Identify the components**: The name suggests copper (Cu) as the central metal with two chloride ions (Cl) and two urea (NH2CO) ligands.
2. **Determine oxidation states**:
- Copper (Cu) is given as +2.
- Each urea is neutral (0 oxidation state), and there are two urea molecules: \(2 \times 0 = 0\).
- Each chloride ion (Cl) has an oxidation state of -1, and there are two chloride ions: \(2 \times (-1) = -2\).
3. **Calculate the total oxidation state of the complex**:
- The total from chloride is -2. The oxidation state of copper is +2, leading to a total of \(+2 - 2 = 0\).
4. **Check overall charge**:
- The total charge from the complex is 0, meaning this complex can exist without a counter ion, making this name possible.

### Conclusion
After analyzing all options, we conclude that the impossible name is **Option A - Potassium Tetrafluoridophus**.