Boron reacts with oxygen at `700^@C` to give `(A)`. Compound `(A)` reacts with carbon and dry chloride to give `(B)` and carbon monoxide. `(B)` on reduction with `LiAlH_(4)` gives `( C)` along with `LiCl` and `AlCl_(3). ( C)` on reaction with ammonia gives `(D)`. Which on heating gives `(E).(C)` on reaction with `NaH` gives `(F)`.
Compound `(A)` is

Options

A. `BO_(3)`
B. `B_(2)O_(3)`
C. `BO_(2)`
D. `B_(4)O_(6)`

Explanation

To solve the question step by step, we will analyze the reactions involving boron and its compounds as described in the problem.

### Step 1: Identify Compound (A)
Boron reacts with oxygen at `700°C`. The reaction can be represented as:
\[ 4B + 3O_2 \rightarrow 2B_2O_3 \]
Thus, the compound (A) formed is **B2O3** (Boron trioxide).

### Step 2: Identify Compound (B)
Compound (A) reacts with carbon and dry chloride to give compound (B) and carbon monoxide. The reaction can be represented as:
\[ B_2O_3 + 3C + 3Cl_2 \rightarrow 2BCl_3 + 3CO \]
Thus, the compound (B) formed is **BCl3** (Boron trichloride).

### Step 3: Identify Compound (C)
Compound (B) reacts with lithium aluminum hydride (LiAlH4) to give compound (C) along with LiCl and AlCl3. The reaction can be represented as:
\[ 4BCl_3 + 3LiAlH_4 \rightarrow 2B_2H_6 + 3LiCl + 3AlCl_3 \]
Thus, the compound (C) formed is **B2H6** (Diborane).

### Step 4: Identify Compound (D)
Compound (C) reacts with ammonia to give compound (D). The reaction can be represented as:
\[ B_2H_6 + 2NH_3 \rightarrow B_2H_6 \cdot 2NH_3 \]
Thus, the compound (D) formed is **B2H6·2NH3** (Diborane-ammonia complex).

### Step 5: Identify Compound (E)
Compound (D) on heating gives compound (E). The reaction can be represented as:
\[ B_2H_6 \cdot 2NH_3 \xrightarrow{heat} B_3N_3H_6 \]
Thus, the compound (E) formed is **B3N3H6** (Borazine).

### Step 6: Identify Compound (F)
Compound (C) reacts with sodium hydride (NaH) to give compound (F). The reaction can be represented as:
\[ B_2H_6 + NaH \rightarrow NaBH_4 \]
Thus, the compound (F) formed is **NaBH4** (Sodium borohydride).

### Final Answer
The compound (A) is **B2O3** (Boron trioxide).

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