A compound made of two elements A and B is found to contains
25% A (atomic mass 12.5) and 75% B (atomic mass 37.5). The
simplest formula of the the compound is :-

Options

A. AB
B. `A_(2)B_(2)`
C. `AB_(3)`
D. `A_(3)B`

Explanation

To determine the simplest formula of the compound made of elements A and B, we can follow these steps:

### Step 1: Identify the given data
- Percentage of element A = 25%
- Atomic mass of element A = 12.5 g/mol
- Percentage of element B = 75%
- Atomic mass of element B = 37.5 g/mol

### Step 2: Calculate the number of moles of each element
To find the number of moles, we use the formula:
\[ \text{Number of moles} = \frac{\text{Weight \%}}{\text{Atomic mass}} \]

**For element A:**
\[ \text{Number of moles of A} = \frac{25}{12.5} = 2 \text{ moles} \]

**For element B:**
\[ \text{Number of moles of B} = \frac{75}{37.5} = 2 \text{ moles} \]

### Step 3: Determine the simplest mole ratio
Now we need to find the simplest ratio of moles of A to moles of B:
- Moles of A = 2
- Moles of B = 2

To find the simplest ratio, we divide both values by the smallest number of moles:
\[ \text{Ratio of A to B} = \frac{2}{2} : \frac{2}{2} = 1 : 1 \]

### Step 4: Write the simplest formula
From the mole ratio of 1:1, we can conclude that the simplest formula of the compound is:
\[ \text{AB} \]

### Final Answer:
The simplest formula of the compound is **AB**.

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