The correct formula for ammonium phosphate is

Options

A. `N_2H_6PO_4`
B. `(NH_3)_3PO_4`
C. `(NH_4)_3PO_4`
D. `(NH_4)_2PO_4`

Explanation

To determine the correct formula for ammonium phosphate, we need to follow these steps:

### Step 1: Identify the ions involved
- **Ammonium ion**: The formula for the ammonium ion is \( \text{NH}_4^+ \).
- **Phosphate ion**: The formula for the phosphate ion is \( \text{PO}_4^{3-} \).

### Step 2: Determine the charges of the ions
- The ammonium ion has a charge of \( +1 \).
- The phosphate ion has a charge of \( -3 \).

### Step 3: Balance the charges
To create a neutral compound, the total positive charge must equal the total negative charge.
- We have 3 negative charges from one phosphate ion (\( \text{PO}_4^{3-} \)).
- To balance these 3 negative charges, we need 3 positive charges.

### Step 4: Calculate the number of ammonium ions needed
Since each ammonium ion contributes \( +1 \) charge, we need 3 ammonium ions to balance the \( -3 \) charge from one phosphate ion:
- Therefore, we need \( 3 \times \text{NH}_4^+ \).

### Step 5: Write the formula for the compound
Now that we have determined the number of each ion needed:
- The formula will consist of 3 ammonium ions and 1 phosphate ion, which can be written as:
\[ \text{(NH}_4\text{)}_3\text{PO}_4 \]

### Final Answer
The correct formula for ammonium phosphate is:
\[ \text{(NH}_4\text{)}_3\text{PO}_4 \]

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