The oxide of element possesses the formula `MO_(2)`. If the equivalent mass of the metal is 9. then the atomic mass of the metal will be

Options

A. 9
B. 18
C. 27
D. 36

Explanation

To find the atomic mass of the metal (M) in the oxide \( MO_2 \) given that the equivalent mass of the metal is 9, we can follow these steps:

### Step 1: Understand the Oxide Formula
The oxide has the formula \( MO_2 \). This indicates that for every one atom of metal (M), there are two atoms of oxygen (O).

### Step 2: Determine the Charge of the Metal
Oxygen typically has a charge of -2. Since there are two oxygen atoms in the oxide, the total negative charge contributed by oxygen is:
\[ \text{Total charge from oxygen} = 2 \times (-2) = -4 \]
To balance this, the metal must have a charge of +4.

### Step 3: Identify the n Factor
The n factor for the metal in this case is the charge it carries, which we determined to be +4.

### Step 4: Use the Formula for Equivalent Mass
The formula for equivalent mass is given by:
\[ \text{Equivalent mass} = \frac{\text{Atomic mass}}{n \text{ factor}} \]
We know the equivalent mass of the metal is 9 and the n factor is 4.

### Step 5: Set Up the Equation
Substituting the known values into the formula:
\[ 9 = \frac{\text{Atomic mass}}{4} \]

### Step 6: Solve for Atomic Mass
To find the atomic mass, we can rearrange the equation:
\[ \text{Atomic mass} = 9 \times 4 \]
Calculating this gives:
\[ \text{Atomic mass} = 36 \]

### Conclusion
The atomic mass of the metal is 36.

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