Which one of the following compounds has iodine in it’s the highest oxidation state ?

Options

A. KI
B. `KI_3`
C. `IF_5`
D. `KIO_4`

Answer

To determine which compound has iodine in its highest oxidation state, we will analyze the oxidation states of iodine in each of the given compounds.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds we need to analyze are:
- Potassium iodide (KI)
- Iodine trifluoride (IF3)
- Iodine pentafluoride (IF5)
- Potassium periodate (KIO4)

2. **Calculate the Oxidation State of Iodine in Potassium Iodide (KI)**:
- Potassium (K) has an oxidation state of +1.
- The compound is neutral, so the sum of oxidation states must equal 0.
- Let the oxidation state of iodine be \( x \).
- The equation is:
\[ +1 + x = 0 \implies x = -1 \]
- **Oxidation state of iodine in KI = -1**.

3. **Calculate the Oxidation State of Iodine in Iodine Trifluoride (IF3)**:
- Fluorine (F) has an oxidation state of -1.
- The equation is:
\[ x + 3(-1) = 0 \implies x - 3 = 0 \implies x = +3 \]
- **Oxidation state of iodine in IF3 = +3**.

4. **Calculate the Oxidation State of Iodine in Iodine Pentafluoride (IF5)**:
- Again, fluorine (F) has an oxidation state of -1.
- The equation is:
\[ x + 5(-1) = 0 \implies x - 5 = 0 \implies x = +5 \]
- **Oxidation state of iodine in IF5 = +5**.

5. **Calculate the Oxidation State of Iodine in Potassium Periodate (KIO4)**:
- Potassium (K) has an oxidation state of +1 and oxygen (O) has an oxidation state of -2.
- The equation is:
\[ +1 + x + 4(-2) = 0 \implies +1 + x - 8 = 0 \implies x - 7 = 0 \implies x = +7 \]
- **Oxidation state of iodine in KIO4 = +7**.

6. **Compare the Oxidation States**:
- KI: -1
- IF3: +3
- IF5: +5
- KIO4: +7

7. **Conclusion**: The highest oxidation state of iodine is found in potassium periodate (KIO4), which is +7.

### Final Answer:
The compound with iodine in its highest oxidation state is **KIO4**.