What is the normality of a 1 M solution of H3PO4

Options

A. 0.5
B. 1
C. 2
D. 3

Answer

To find the normality of a 1 M solution of H3PO4 (phosphoric acid), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Acid Type**:
- H3PO4 is known as phosphoric acid. It is classified as a tribasic acid because it can donate three hydrogen ions (H⁺) in a reaction.

2. **Understand the Concept of Normality**:
- Normality (N) is a measure of concentration equivalent to molarity (M) multiplied by the number of equivalents of the solute. For acids, the number of equivalents is equal to the number of hydrogen ions that can be donated.

3. **Calculate Normality**:
- Since H3PO4 can donate three hydrogen ions, the normality can be calculated using the formula:
\[ \text{Normality (N)} = \text{Molarity (M)} \times \text{Number of H⁺ ions} \]
- In this case, the molarity of the solution is 1 M, and the number of replaceable hydrogen ions is 3.
- Therefore:
\[ \text{Normality} = 1 \, \text{M} \times 3 = 3 \, \text{N} \]

4. **Conclusion**:
- The normality of a 1 M solution of H3PO4 is 3 N.

### Final Answer:
The normality of a 1 M solution of H3PO4 is **3 N**.

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