How many moles of sodium carbonate contain 1.773 × 1017 carbon atoms?

Explanation:

1) Chemical formula of sodium carbonate: Na₂CO₃

2) Ratio of carbon atoms:

Hence, the ratio is 1 C atom / 1 Na₂CO₃ unit formula.

This is, there is 1 atom of carbon per each unit formula of sodium carbonate.

3) Calculate the number of moles in 1.773 × 10⁷ carbon atoms

Since, the ratio is 1: 1, the number of moles of sodium carbonate is the same number of moles of carbon atoms.

the answer is option a.