An element 'A' burns in nitrogen to give an ionic compound 'B' which reacts with water to give 'C' and D. 'E' is used in white washing. Identify, A, B, C and D:

Options

A. `Ca , Cl_2 , Ca(OH)_2 , N_2`
B. `Ca, Ca_3 N_2 , Ca(OH)_2 , NH_3`
C. `Ca, Ca(OH)_2 , CaCO_3 , NH_3`
D. `Ca , Cl_2 , Ca(OH)_2 , NH_3`

Explanation

To solve the problem step by step, let's identify the elements and compounds involved based on the information provided.

### Step 1: Identify Element A
The question states that element 'A' burns in nitrogen to form an ionic compound 'B'. The element used in whitewashing is typically calcium. Therefore, we can conclude:
- **A = Calcium (Ca)**

**Hint:** Think about common elements that react with nitrogen and are used in construction or household applications.

### Step 2: Identify Ionic Compound B
When calcium reacts with nitrogen, it forms calcium nitride, which is an ionic compound. Thus, we have:
- **B = Calcium Nitride (Ca3N2)**

**Hint:** Consider the type of compounds formed when metals react with non-metals, especially nitrogen.

### Step 3: Identify Compounds C and D
The question states that compound 'B' reacts with water to produce compounds 'C' and 'D'. Calcium nitride reacts with water to produce calcium hydroxide and ammonia. Therefore:
- **C = Calcium Hydroxide (Ca(OH)2)**
- **D = Ammonia (NH3)**

**Hint:** Recall the products formed when metal nitrides react with water; they often yield hydroxides and ammonia.

### Summary of Identifications
- **A = Calcium (Ca)**
- **B = Calcium Nitride (Ca3N2)**
- **C = Calcium Hydroxide (Ca(OH)2)**
- **D = Ammonia (NH3)**

### Final Answer
- A: Calcium (Ca)
- B: Calcium Nitride (Ca3N2)
- C: Calcium Hydroxide (Ca(OH)2)
- D: Ammonia (NH3)