Ferric alum has the composition
`(NH_(4))_(2)SO_(4). Fe_(2)(SO_(4)).xH_(2)O.x` is

Options

A. 7
B. 24
C. 6
D. 15

Explanation

To determine the value of \( x \) in the composition of ferric alum, we need to analyze the given formula:

\[ (NH_4)_2SO_4 \cdot Fe_2(SO_4)_3 \cdot xH_2O \]

### Step 1: Identify the components of ferric alum

Ferric alum consists of:
- Ammonium sulfate \((NH_4)_2SO_4\)
- Ferric sulfate \(Fe_2(SO_4)_3\)
- Water of crystallization \(xH_2O\)

### Step 2: Write the complete formula

The complete formula of ferric alum can be expressed as:

\[ (NH_4)_2SO_4 \cdot Fe_2(SO_4)_3 \cdot xH_2O \]

### Step 3: Determine the number of water molecules

From the video transcript, it is mentioned that the formula of ferric alum is:

\[ (NH_4)_2SO_4 \cdot Fe_2(SO_4)_3 \cdot 24H_2O \]

This indicates that the value of \( x \) is 24.

### Step 4: Conclusion

Thus, the value of \( x \) in the formula of ferric alum is:

\[ \boxed{24} \]

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