Concept:Empirical formulas are determined by converting mass percentages to relative moles, and then normalizing those moles into the simplest whole-number ratio.
Formula:$$ \text{Moles} = \frac{\% \text{ Composition}}{\text{Atomic Mass}} $$
Solution:- For Carbon: \( 40.0 / 12 = 3.33 \text{ moles} \).
- For Hydrogen: \( 6.67 / 1.008 \approx 6.67 \text{ moles} \).
- For Oxygen: \( 53.3 / 16 = 3.33 \text{ moles} \).
- Identify the smallest mole value, which is 3.33, and divide all values by it.
- C ratio = \( 3.33 / 3.33 = 1 \).
- H ratio = \( 6.67 / 3.33 = 2 \).
- O ratio = \( 3.33 / 3.33 = 1 \).
- The simplest whole-number ratio is 1:2:1, yielding the empirical formula \( \text{CH}_2\text{O} \) (which is the baseline for carbohydrates).
Why other options are incorrect:- \( \text{CH}_3\text{O}, \text{C}_2\text{H}_3\text{O}, \text{C}_2\text{H}_2\text{O} \): These formulas disrupt the strict 1:2:1 mathematical ratio resulting from the mass percentage division.
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