Dissociation of `H_(3)PO_(4)` takes place in following steps

Options

A. 1
B. 2
C. 3
D. 4

Explanation

To understand the dissociation of phosphoric acid (H₃PO₄), we can break it down into its stepwise dissociation reactions. Phosphoric acid is a triprotic acid, meaning it can donate three protons (H⁺ ions) in a stepwise manner. Here’s the step-by-step dissociation process:

### Step 1: First Dissociation
The first dissociation of phosphoric acid occurs when it donates one proton to form dihydrogen phosphate (H₂PO₄⁻):

\[ \text{H}_3\text{PO}_4 (aq) \rightleftharpoons \text{H}^+ (aq) + \text{H}_2\text{PO}_4^- (aq) \]

### Step 2: Second Dissociation
In the second step, dihydrogen phosphate (H₂PO₄⁻) can donate another proton to form hydrogen phosphate (HPO₄²⁻):

\[ \text{H}_2\text{PO}_4^- (aq) \rightleftharpoons \text{H}^+ (aq) + \text{HPO}_4^{2-} (aq) \]

### Step 3: Third Dissociation
Finally, in the third step, hydrogen phosphate (HPO₄²⁻) can donate a proton to form phosphate (PO₄³⁻):

\[ \text{HPO}_4^{2-} (aq) \rightleftharpoons \text{H}^+ (aq) + \text{PO}_4^{3-} (aq) \]

### Summary of Dissociation Steps
1. **First Dissociation**: H₃PO₄ → H⁺ + H₂PO₄⁻
2. **Second Dissociation**: H₂PO₄⁻ → H⁺ + HPO₄²⁻
3. **Third Dissociation**: HPO₄²⁻ → H⁺ + PO₄³⁻