1. What is an Empirical Formula?

The empirical formula of a compound gives the simplest whole number ratio of atoms of each element present in the compound. It represents the relative number of atoms of each element in the substance.

2. How the Calculator Works

The calculator follows these steps:

3. Step-by-Step Calculation

Example: For a compound with 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen:

• Carbon: 40.0g / 12.01g/mol = 3.33 moles
• Hydrogen: 6.7g / 1.01g/mol = 6.63 moles
• Oxygen: 53.3g / 16.00g/mol = 3.33 moles
• Divide by smallest (3.33): C=1, H=1.99, O=1
• Round: CH₂O

4. Using the Calculator

Instructions:

1. Enter each element's symbol (C, H, O, etc.)
2. Enter the percentage composition for each element
3. Enter the atomic mass of each element
4. Click "Add Another Element" if needed
5. Click "Calculate" to get the empirical formula

5. Frequently Asked Questions (FAQ)

Q1: What if my percentages don't add up to exactly 100%?
A: Small deviations are normal due to rounding. The calculator will work with any reasonable total (90-110%).

Q2: How do I handle ratios that aren't whole numbers?
A: If you get ratios like 1.5, multiply all ratios by 2 to get whole numbers (e.g., 1.5 becomes 3).

Q3: What's the difference between empirical and molecular formula?
A: The molecular formula shows the actual number of atoms, while empirical shows the simplest ratio. Example: C₆H₁₂O₆ (molecular) vs CH₂O (empirical).

Q4: Can I use this for ionic compounds?
A: Yes, ionic compounds are always represented by their empirical formulas (e.g., NaCl).

Q5: What if my rounded ratios are very close but not exact?
A: Common fractions like 0.33, 0.25, 0.2, and 0.5 can be multiplied by 3, 4, 5, and 2 respectively to get whole numbers.