Concept:Within a chemical formula, there is a fixed ratio between the moles of the whole compound and the mass of the elements inside it.
Formula:$$ \text{Moles of compound} = \frac{\text{Given mass of element}}{\text{Mass of element in 1 mole of compound}} $$
Solution:- The formula for Carbon dioxide is \( \text{CO}_2 \).
- One complete mole of \( \text{CO}_2 \) inherently contains 2 moles of Oxygen atoms.
- The mass of these 2 moles of Oxygen atoms is \( 2 \times 16 = 32 \text{ grams} \).
- We are told the sample only contains 16 g of oxygen (which is exactly half of 32 g).
- Therefore, we must only have exactly half a mole of \( \text{CO}_2 \).
- Moles of \( \text{CO}_2 = 16 / 32 = 0.5 \text{ moles} \).
Why other options are incorrect:- 1.00: This would require a full 32g of oxygen.
- 0.25: This would mean the sample only contained 8g of oxygen.
- 1.50: This would mean the sample contained 48g of oxygen.
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