The phosphate of a metal has the formula `MHPO_(4)`. The formula of its chloride would be

Options

A. MCl
B. `MCl_(2)`
C. `MCl_(3)`
D. `M_(2)Cl_(3)`

Answer

To determine the formula of the chloride of a metal whose phosphate is represented as \( MHPO_4 \), we can follow these steps:

### Step 1: Analyze the Phosphate Ion
The phosphate ion is represented as \( PO_4^{3-} \). When we add a hydrogen ion (\( H^+ \)) to it, the charge changes.

- \( HPO_4^{2-} \) is formed when one hydrogen is added.
- \( H_2PO_4^{-} \) is formed when two hydrogens are added.
- \( H_3PO_4 \) is formed when three hydrogens are added.

In this case, since the formula is \( MHPO_4 \), we identify that \( HPO_4^{2-} \) is present.

### Step 2: Determine the Oxidation State of the Metal
In the formula \( MHPO_4 \):
- The \( HPO_4^{2-} \) ion has a charge of -2.
- Therefore, the metal \( M \) must have a charge of +2 to balance the overall charge to zero.

### Step 3: Identify the Chloride Ion
The chloride ion is represented as \( Cl^{-} \) and has a charge of -1.

### Step 4: Write the Formula for the Chloride
To find the formula for the chloride of the metal \( M \), we need to balance the charges:
- The metal \( M \) has a charge of +2.
- The chloride ion has a charge of -1.

To balance the charges, we need two chloride ions for every one metal ion. Thus, the formula for the chloride will be:

\[ MCl_2 \]

### Conclusion
The formula of the chloride of the metal is \( MCl_2 \).

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