What is the empirical formula for a compound that contains 17.34% hydrogen and 82.66% carbon by mass?

• A. C2H2
• B. CH4
• C. C2H4
• D. CH2

Answer: (D)

Verified step by step guidance

1. Step 1: Assume you have 100 grams of the compound. This means you have 17.34 grams of hydrogen and 82.66 grams of carbon.
2. Step 2: Convert the masses of each element to moles by dividing by their atomic masses: hydrogen (H) has an atomic mass of approximately 1.008 g/mol, and carbon (C) has an atomic mass of approximately 12.01 g/mol. Use the formulas: \(\text{moles of H} = \frac{17.34}{1.008}\) and \(\text{moles of C} = \frac{82.66}{12.01}\).
3. Step 3: Determine the simplest whole number mole ratio by dividing both mole values by the smaller number of moles obtained in Step 2.
4. Step 4: If the mole ratios are not whole numbers, multiply both ratios by the smallest factor that converts them into whole numbers.
5. Step 5: Write the empirical formula using the whole number mole ratios as subscripts for each element, with carbon (C) first followed by hydrogen (H).