Chromium has the lowest oxidation state in

Options

A. potassium chromate
B. chromium sulphate
C. potassium dichromate
D. chromium oxide

Answer

To determine the lowest oxidation state of chromium in the given compounds, we will analyze each compound step by step.

### Step 1: Identify the compounds and their formulas
The compounds given are:
1. Potassium bromate - K2CrO4
2. Chromium sulfate - Cr2(SO4)3
3. Potassium dichromate - K2Cr2O7
4. Chromium oxide - Cr2O3

### Step 2: Calculate the oxidation state of chromium in each compound

**1. Potassium bromate (K2CrO4)**
- The formula is K2CrO4.
- Potassium (K) has an oxidation state of +1.
- Oxygen (O) has an oxidation state of -2.
- Let the oxidation state of chromium (Cr) be x.
- The equation can be set up as follows:
\( 2(+1) + x + 4(-2) = 0 \)
\( 2 + x - 8 = 0 \)
\( x - 6 = 0 \)
\( x = +6 \)

**2. Chromium sulfate (Cr2(SO4)3)**
- The formula is Cr2(SO4)3.
- Each sulfate (SO4) has an oxidation state of -2.
- Let the oxidation state of chromium be x.
- The equation can be set up as follows:
\( 2x + 3(-2) = 0 \)
\( 2x - 6 = 0 \)
\( 2x = 6 \)
\( x = +3 \)

**3. Potassium dichromate (K2Cr2O7)**
- The formula is K2Cr2O7.
- Potassium (K) has an oxidation state of +1.
- Oxygen (O) has an oxidation state of -2.
- Let the oxidation state of chromium be x.
- The equation can be set up as follows:
\( 2(+1) + 2x + 7(-2) = 0 \)
\( 2 + 2x - 14 = 0 \)
\( 2x - 12 = 0 \)
\( 2x = 12 \)
\( x = +6 \)

**4. Chromium oxide (Cr2O3)**
- The formula is Cr2O3.
- Oxygen (O) has an oxidation state of -2.
- Let the oxidation state of chromium be x.
- The equation can be set up as follows:
\( 2x + 3(-2) = 0 \)
\( 2x - 6 = 0 \)
\( 2x = 6 \)
\( x = +3 \)

### Step 3: Compare the oxidation states
- Potassium bromate (K2CrO4): +6
- Chromium sulfate (Cr2(SO4)3): +3
- Potassium dichromate (K2Cr2O7): +6
- Chromium oxide (Cr2O3): +3

### Conclusion
The lowest oxidation state of chromium is +3, which occurs in both chromium sulfate and chromium oxide.

### Final Answer
Chromium has the lowest oxidation state in **Chromium sulfate (Cr2(SO4)3)** and **Chromium oxide (Cr2O3)**.

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