A compound made of two elements A and B are found to contain 25 % A (at. mass `12*5`) and 75% B (at. mass `37*5`) The simplest formula of the compound is

Options

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

Explanation

To find the simplest formula of the compound made of elements A and B, we need to follow these steps:

### Step 1: Determine the mass of each element in a 100 g sample
Since the percentages are given, we can assume we have 100 g of the compound. This means:
- Mass of A = 25% of 100 g = 25 g
- Mass of B = 75% of 100 g = 75 g

### Step 2: Calculate the number of moles of each element
To find the number of moles, we use the formula:
\[ \text{Number of moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}} \]

For element A:
- Atomic mass of A = 12.5 g/mol
\[ \text{Moles of A} = \frac{25 \, \text{g}}{12.5 \, \text{g/mol}} = 2 \, \text{moles} \]

For element B:
- Atomic mass of B = 37.5 g/mol
\[ \text{Moles of B} = \frac{75 \, \text{g}}{37.5 \, \text{g/mol}} = 2 \, \text{moles} \]

### Step 3: Find the simplest mole ratio
Now we compare the number of moles of A and B:
- Moles of A = 2
- Moles of B = 2

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

### Step 4: Write the empirical formula
Since the ratio of moles of A to B is 1:1, the simplest formula of the compound is:
\[ \text{Empirical formula} = AB \]

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

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