The molarity of `0.6N` phosphorous acid is

Options

A. 0.3
B. 0.1
C. 0.9
D. 0.6

Explanation

To find the molarity of 0.6 N phosphorous acid, we can follow these steps:

### Step 1: Understand the relationship between normality and molarity
Normality (N) is related to molarity (M) through the equation:
\[ N = M \times \text{Basicity} \]
Where Basicity refers to the number of H⁺ ions that can be replaced by the acid.

### Step 2: Identify the normality given in the problem
The problem states that the normality of phosphorous acid is 0.6 N.

### Step 3: Determine the basicity of phosphorous acid
Phosphorous acid (H₃PO₃) has the following structure:
- It contains three hydrogen atoms, but only two of them are ionizable (replaceable) as H⁺ ions.
- Therefore, the basicity of phosphorous acid is 2.

### Step 4: Rearrange the equation to find molarity
Using the relationship from Step 1, we can rearrange the equation to solve for molarity:
\[ M = \frac{N}{\text{Basicity}} \]

### Step 5: Substitute the values into the equation
Now, substituting the known values into the equation:
\[ M = \frac{0.6 \, N}{2} \]

### Step 6: Calculate the molarity
Perform the calculation:
\[ M = \frac{0.6}{2} = 0.3 \, M \]

### Final Answer
The molarity of 0.6 N phosphorous acid is **0.3 M**.

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