Which pair of products are formed when amorphous boron is burned in air?

Options

A. `B_2O_3 and BN`
B. `B_2N_3 and B_2O_3`
C. Borazine and `H_3BO_3`
D. `B_2O_3 and B_2H_6`

Answer

To determine the products formed when amorphous boron is burned in air, we can follow these steps:

### Step 1: Understand the Reaction
When amorphous boron is burned in air, it reacts primarily with the oxygen present in the air.

### Step 2: Identify the Products
The main products formed from the combustion of boron in air are:
1. Boron trioxide (B2O3)
2. Boron nitride (BN)

### Step 3: Determine the Formation of Boron Trioxide
When boron reacts with oxygen, it forms boron trioxide (B2O3). The reaction can be represented as:
\[ 4B + 3O_2 \rightarrow 2B_2O_3 \]
In this reaction, the oxidation state of boron changes from 0 to +3.

### Step 4: Determine the Formation of Boron Nitride
In addition to forming boron trioxide, boron can also react with nitrogen present in the air to form boron nitride (BN). The reaction can be represented as:
\[ B + N_2 \rightarrow BN \]
Here, the oxidation state of boron is +3 and nitrogen is -3.

### Step 5: Conclusion
Thus, when amorphous boron is burned in air, the two main products formed are:
- Boron trioxide (B2O3)
- Boron nitride (BN)

### Final Answer
The pair of products formed when amorphous boron is burned in air are B2O3 (boron trioxide) and BN (boron nitride).

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