A metal oxide contains 60% metal . The equivalent weight of metal is

Options

A. 12
B. 60
C. 40
D. 24

Answer

To find the equivalent weight of the metal in the metal oxide that contains 60% metal, we can follow these steps:

### Step-by-Step Solution:

1. **Determine the Mass of Metal and Oxygen:**
- Assume we have 100 grams of the metal oxide.
- Since the metal oxide contains 60% metal, the mass of the metal is:
\[ \text{Mass of metal} = 60\% \text{ of } 100 \text{ grams} = 60 \text{ grams} \]
- The remaining mass is oxygen:
\[ \text{Mass of oxygen} = 100 \text{ grams} - 60 \text{ grams} = 40 \text{ grams} \]

2. **Calculate the Equivalent Weight of Oxygen:**
- The atomic mass of oxygen (O) is 16 grams.
- Since oxygen typically has a valency of 2 in oxides, the equivalent weight of oxygen is calculated as:
\[ \text{Equivalent weight of oxygen} = \frac{\text{Atomic mass of oxygen}}{\text{Valency}} = \frac{16}{2} = 8 \text{ grams} \]

3. **Determine the Number of Equivalents of Oxygen:**
- The number of equivalents of oxygen in 40 grams can be calculated as:
\[ \text{Number of equivalents of oxygen} = \frac{\text{Mass of oxygen}}{\text{Equivalent weight of oxygen}} = \frac{40 \text{ grams}}{8 \text{ grams}} = 5 \text{ equivalents} \]

4. **Calculate the Equivalent Weight of Metal:**
- The mass of metal that corresponds to these 5 equivalents can be calculated. We know that 60 grams of metal corresponds to 5 equivalents of oxygen:
- Therefore, the equivalent weight of the metal can be calculated as:
\[ \text{Equivalent weight of metal} = \frac{\text{Mass of metal}}{\text{Number of equivalents of oxygen}} = \frac{60 \text{ grams}}{5} = 12 \text{ grams} \]

5. **Conclusion:**
- The equivalent weight of the metal is 12 grams.

### Final Answer:
The equivalent weight of the metal is **12 grams**.

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