A compound contains 28% N and 72% of a metal by weight . Three atoms of metal combine with two atoms of N . Find the atomic weight of metal.

Options

A. 12
B. 32
C. 24
D. 16

Answer

To solve the problem step by step, we can follow these instructions:

### Step 1: Understand the composition of the compound
The compound contains:
- 28% Nitrogen (N)
- 72% Metal (M)

### Step 2: Determine the total weight of the compound
Assuming we have 100 grams of the compound, we can directly use the percentages to find the weights:
- Weight of Nitrogen = 28 grams
- Weight of Metal = 72 grams

### Step 3: Establish the relationship between the atoms
According to the problem, 3 atoms of Metal combine with 2 atoms of Nitrogen. This gives us a ratio of:
- 3 M : 2 N

### Step 4: Calculate the weight of Nitrogen in the compound
The atomic weight of Nitrogen (N) is approximately 14 g/mol. Therefore, the weight of 2 nitrogen atoms is:
- Weight of 2 N = 2 × 14 g = 28 grams

### Step 5: Calculate the weight of Metal in the compound
From the total weight of the compound, we know that the weight of 3 metal atoms is:
- Weight of 3 M = 72 grams

### Step 6: Find the weight of one metal atom
To find the weight of one metal atom, we divide the total weight of the metal by the number of metal atoms:
- Weight of 1 M = Weight of 3 M / 3 = 72 grams / 3 = 24 grams

### Step 7: Conclusion
The atomic weight of the metal is 24 grams.

### Final Answer
The atomic weight of the metal is **24 g/mol**.

---