Heats of atmoisation of ozone and oxygen are 25 units and 30 units respectively. What is the heat of ozonisation of one mole of oxygen is the same units?

Answer

To find the heat of ozonization of one mole of oxygen, we can use the heats of atomization of ozone (O3) and oxygen (O2) given in the question. Here’s a step-by-step solution:

### Step 1: Understanding the Reaction
We know that ozone (O3) can be formed from oxygen (O2). The balanced chemical equation for the formation of ozone from oxygen is:
\[ 3 \text{O}_2 \rightarrow 2 \text{O}_3 \]

### Step 2: Write Down the Heats of Atomization
The heats of atomization given are:
- Heat of atomization of ozone (O3) = 25 units
- Heat of atomization of oxygen (O2) = 30 units

### Step 3: Relate the Heats of Atomization to the Reaction
From the balanced equation, we can relate the heats of atomization to the formation of ozone from oxygen. The heat change for the reaction can be expressed as:
\[ \Delta H = \text{(Heat of formation of products)} - \text{(Heat of formation of reactants)} \]

For the reaction:
\[ 3 \text{O}_2 \rightarrow 2 \text{O}_3 \]

The heat change can be written as:
\[ \Delta H = 2 \times \text{(Heat of atomization of O3)} - 3 \times \text{(Heat of atomization of O2)} \]

### Step 4: Substitute the Values
Substituting the values we have:
\[ \Delta H = 2 \times 25 - 3 \times 30 \]
\[ \Delta H = 50 - 90 \]
\[ \Delta H = -40 \text{ units} \]

### Step 5: Calculate the Heat of Ozonization for One Mole of O2
Now, we need to find the heat of ozonization for one mole of O2. Since the reaction shows that 3 moles of O2 produce 2 moles of O3, we can find the heat of ozonization for one mole of O2:
\[ \text{Heat of ozonization for 1 mole of O2} = \frac{-40}{3} \]

Calculating this gives:
\[ \text{Heat of ozonization for 1 mole of O2} = -\frac{40}{3} \approx -13.33 \text{ units} \]

### Final Answer
Thus, the heat of ozonization of one mole of oxygen is approximately **-13.33 units**.

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