A compound contains `C=90%` and `H=10%` Empirical formula of the compound is:

Options

A. `C_(15)H_(30)`
B. `C_(15)H_(20)`
C. `C_3H_4`
D. `C_3H_(10)`

Explanation

To find the empirical formula of a compound that contains 90% carbon (C) and 10% hydrogen (H), we can follow these steps:

### Step 1: Convert the percentages to grams
Assume we have 100 grams of the compound. This means:
- Carbon: 90 grams
- Hydrogen: 10 grams

### Step 2: Convert grams to moles
To convert grams to moles, we use the formula:
\[ \text{Moles} = \frac{\text{Mass (g)}}{\text{Molar Mass (g/mol)}} \]
- Molar mass of Carbon (C) = 12 g/mol
- Molar mass of Hydrogen (H) = 1 g/mol

Calculating the moles:
- Moles of Carbon = \( \frac{90 \text{ g}}{12 \text{ g/mol}} = 7.5 \text{ moles} \)
- Moles of Hydrogen = \( \frac{10 \text{ g}}{1 \text{ g/mol}} = 10 \text{ moles} \)

### Step 3: Find the simplest mole ratio
Now, we need to find the simplest ratio of moles of C to H:
- Ratio of C to H = \( \frac{7.5}{7.5} : \frac{10}{7.5} \)
- This simplifies to \( 1 : \frac{10}{7.5} = 1 : 1.33 \)

### Step 4: Convert to whole numbers
To convert the ratio to whole numbers, we can multiply both parts of the ratio by 3 (to eliminate the fraction):
- Carbon: \( 1 \times 3 = 3 \)
- Hydrogen: \( 1.33 \times 3 \approx 4 \)

### Step 5: Write the empirical formula
Now we can write the empirical formula based on the whole number ratio:
- Empirical formula = \( C_3H_4 \)

### Final Answer
The empirical formula of the compound is \( C_3H_4 \).

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