Select the correct order of acidic strength of following oxides:

Q: Select the correct order of acidic strength of following oxides:

Select the correct order of acidic strength of following oxides:

Question

Accepted Answer

The correct order of acidic strength of the given oxides is provided as Option 4: $SO_{3}>CO_{2}>B_{2}O_{3}$. Let's explore why this is the correct order and why the other options are incorrect.

### Explanation for Option 4:

1. **$SO_{3}$ (Sulfur trioxide):** 
   - $SO_{3}$ is a highly acidic oxide. It reacts with water to form sulfuric acid ($H_{2}SO_{4}$), which is a strong acid. The high oxidation state of sulfur (+6) in $SO_{3}$ contributes to its strong acidic nature.

2. **$CO_{2}$ (Carbon dioxide):**
   - $CO_{2}$ is an acidic oxide that reacts with water to form carbonic acid ($H_{2}CO_{3}$), which is a weak acid. Although it is less acidic than $SO_{3}$, it is still considered an acidic oxide.

3. **$B_{2}O_{3}$ (Boron trioxide):**
   - $B_{2}O_{3}$ is also an acidic oxide, but it is less acidic compared to $CO_{2}$. It reacts with water to form boric acid ($H_{3}BO_{3}$), which is a very weak acid. Therefore, $B_{2}O_{3}$ is the least acidic among the three.

Thus, the order $SO_{3}>CO_{2}>B_{2}O_{3}$ correctly reflects the decreasing acidic strength of these oxides.

### Explanation for why other options are incorrect:

1. **Option 1: $SO_{2}>SO_{3}>CO_{2}$**
   - $SO_{2}$ is less acidic than $SO_{3}$. $SO_{2}$ forms sulfurous acid ($H_{2}SO_{3}$) when dissolved in water, which is weaker than sulfuric acid. Therefore, $SO_{3}$ should be more acidic than $SO_{2}$, making this option incorrect.

2. **Option 2: $Cs_{2}O>K_{2}O>Na_{2}O$**
   - This option lists basic oxides, not acidic ones. $Cs_{2}O$, $K_{2}O$, and $Na_{2}O$ are all basic oxides, and their order of basicity is not relevant to the question of acidic strength. Therefore, this option is incorrect in the context of acidic strength.

3. **Option 3: $CO_{2}>N_{2}O_{5}>B_{2}O_{3}$**
   - While $CO_{2}$ is more acidic than $B_{2}O_{3}$, $N_{2}O_{5}$ is actually a very strong acidic oxide, forming nitric acid ($HNO_{3}$) in water. It should be more acidic than $CO_{2}$, making this option incorrect in terms of the given order.

In conclusion, Option 4 is the correct answer as it accurately reflects the order of acidic strength among the given oxides: $SO_{3}>CO_{2}>B_{2}O_{3}$.