Answer:
d. 127 g/mol.
Explanation:
Hello!
In this case, since we have the amount of molecules of this this compound, we are able to compute the moles out there by using the Avogadro's number:

Which correspond to the moles of X2. Then, by using the mass we are able to compute the molar mass of X2:

It means that the atomic mass of X halves the molar mass of X2, which is then d. 127 g/mol.
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The small intestine i think :) hope that helps
You need to first write a chemical equation and balance it
C₄H₁₀ + O₂ → CO₂ + H₂O
2 C₄H₁₀ + 13 O₂ → 8 CO₂ + 10 H₂O
1.0 moles X moles
1.0 mol C₄H₁₀ (

) = 4 moles of CO₂