The pair of the compounds in which both the metals are in the highest possible oxidation state is

Options

A. (a) `[Fe(CN)_6]^(3-)`, `[Co(CN)_6]^(3-)`
B. (b) `CrO_2Cl_2`, `MnO_4^(-)`
C. (c) `TiO_3`, `MnO_2`
D. (d) `[Co(CN)_6]^(3-), MnO_3`

Explanation

To determine the pair of compounds in which both metals are in their highest possible oxidation states, we will analyze the oxidation states of the metals in each compound.

### Step-by-Step Solution:

1. **Identify the Compounds**: We need to analyze the given compounds. The compounds mentioned in the video are:
- \( \text{[Fe(CN)_6]^{3-}} \)
- \( \text{[Co(CN)_6]^{3-}} \)
- \( \text{MnO}_4^{-} \)
- \( \text{CrO}_2\text{Cl}_2 \)
- \( \text{TiO}_3 \)
- \( \text{MnO}_2 \)
- \( \text{MnO}_3 \)

2. **Calculate Oxidation States**:
- For \( \text{[Fe(CN)_6]^{3-}} \):
- Let the oxidation state of Fe be \( x \).
- The oxidation state of CN is -1, and there are 6 CN groups.
- Therefore, \( x - 6 = -3 \) → \( x = +3 \).
- For \( \text{[Co(CN)_6]^{3-}} \):
- Let the oxidation state of Co be \( y \).
- Similarly, \( y - 6 = -3 \) → \( y = +3 \).
- For \( \text{MnO}_4^{-} \):
- Let the oxidation state of Mn be \( z \).
- Oxygen is -2, and there are 4 O atoms.
- Therefore, \( z - 8 = -1 \) → \( z = +7 \).
- For \( \text{CrO}_2\text{Cl}_2 \):
- Let the oxidation state of Cr be \( w \).
- Chlorine is -1, and there are 2 Cl atoms, and Oxygen is -2 with 2 O atoms.
- Therefore, \( w - 2 - 2 = -2 \) → \( w = +6 \).
- For \( \text{TiO}_3 \):
- Let the oxidation state of Ti be \( v \).
- Oxygen is -2, and there are 3 O atoms.
- Therefore, \( v - 6 = 0 \) → \( v = +6 \).
- For \( \text{MnO}_2 \):
- Let the oxidation state of Mn be \( u \).
- Therefore, \( u - 4 = 0 \) → \( u = +4 \).
- For \( \text{MnO}_3 \):
- Let the oxidation state of Mn be \( t \).
- Therefore, \( t - 6 = 0 \) → \( t = +6 \).

3. **Determine Highest Oxidation States**:
- **Fe**: +3 (not the highest)
- **Co**: +3 (not the highest)
- **Mn**: +7 (highest)
- **Cr**: +6 (highest)
- **Ti**: +6 (not the highest)
- **Mn in MnO2**: +4 (not the highest)
- **Mn in MnO3**: +6 (not the highest)

4. **Conclusion**: The pair of compounds where both metals are in their highest oxidation states is:
- \( \text{MnO}_4^{-} \) (Mn in +7)
- \( \text{CrO}_2\text{Cl}_2 \) (Cr in +6)

Thus, the answer is \( \text{MnO}_4^{-} \) and \( \text{CrO}_2\text{Cl}_2 \).