Which of the following is correct inceasing order of oxidation number of chlorine in the given compounds ?
I - Sodium chlorite
II - Sodium hypochlorite
III - Sodium perchlorate
IV - Sodium chlorate

Options

A. `I lt II lt III lt IV`
B. `I lt II lt IV lt III`
C. `II lt I lt III lt IV`
D. `II lt I lt IV lt III`

Explanation

To determine the correct increasing order of oxidation numbers of chlorine in the given compounds, we will calculate the oxidation state of chlorine in each compound step by step.

### Step 1: Identify the compounds and their formulas
1. Sodium chlorite - NaClO2
2. Sodium hypochlorite - NaClO
3. Sodium perchlorate - NaClO4
4. Sodium chlorate - NaClO3

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

**For Sodium Hypochlorite (NaClO):**
- Sodium (Na) has an oxidation state of +1.
- Oxygen (O) has an oxidation state of -2.
- Let the oxidation state of chlorine be X.

Using the formula:
\[ +1 + X + (-2) = 0 \]
\[ X - 1 = 0 \]
\[ X = +1 \]

**Oxidation state of chlorine in Sodium Hypochlorite = +1**

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**For Sodium Chlorite (NaClO2):**
- Sodium (Na) has an oxidation state of +1.
- Each Oxygen (O) has an oxidation state of -2, and there are 2 O atoms.

Using the formula:
\[ +1 + X + 2(-2) = 0 \]
\[ +1 + X - 4 = 0 \]
\[ X - 3 = 0 \]
\[ X = +3 \]

**Oxidation state of chlorine in Sodium Chlorite = +3**

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**For Sodium Chlorate (NaClO3):**
- Sodium (Na) has an oxidation state of +1.
- Each Oxygen (O) has an oxidation state of -2, and there are 3 O atoms.

Using the formula:
\[ +1 + X + 3(-2) = 0 \]
\[ +1 + X - 6 = 0 \]
\[ X - 5 = 0 \]
\[ X = +5 \]

**Oxidation state of chlorine in Sodium Chlorate = +5**

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**For Sodium Perchlorate (NaClO4):**
- Sodium (Na) has an oxidation state of +1.
- Each Oxygen (O) has an oxidation state of -2, and there are 4 O atoms.

Using the formula:
\[ +1 + X + 4(-2) = 0 \]
\[ +1 + X - 8 = 0 \]
\[ X - 7 = 0 \]
\[ X = +7 \]

**Oxidation state of chlorine in Sodium Perchlorate = +7**

### Step 3: Summarize the oxidation states
- Sodium Hypochlorite (NaClO): +1
- Sodium Chlorite (NaClO2): +3
- Sodium Chlorate (NaClO3): +5
- Sodium Perchlorate (NaClO4): +7

### Step 4: Arrange in increasing order
The increasing order of oxidation numbers of chlorine is:
1. Sodium Hypochlorite (NaClO): +1
2. Sodium Chlorite (NaClO2): +3
3. Sodium Chlorate (NaClO3): +5
4. Sodium Perchlorate (NaClO4): +7

Thus, the correct increasing order of oxidation number of chlorine in the given compounds is:
**Sodium Hypochlorite < Sodium Chlorite < Sodium Chlorate < Sodium Perchlorate**

### Final Answer
The correct answer is: **Sodium Hypochlorite < Sodium Chlorite < Sodium Chlorate < Sodium Perchlorate**

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