Answer:
D. C2H6
Explanation:
1st) It is necessary to calculate the grams of carbon and hydrogen, knowing that the 30.1g represents the 100% of the mass:
• Carbon:
[tex]\begin{gathered} 100\%-30.1g \\ 80\%-x=\frac{80\%*30.1g}{100\%} \\ x=24.08g \end{gathered}[/tex]• Hydrogen:
[tex]\begin{gathered} 100\%-30.1g \\ 20\%-x=\frac{20\%*30.1g}{100\%} \\ x=6.02g \end{gathered}[/tex]Now we know that there are 24.08g of carbon and 6.02g of hydrogen in the molecule.
2nd) Using the molar mass of carbon (12.04g/mol) and hydrogen (1.003g/mol) we can calculate the moles of each element in the molecule:
• Carbon:
[tex]24.08g*\frac{1mole}{12.04g}=2[/tex]• Hydrogen:
[tex]6.02g*\frac{1mole}{1.003g}=6[/tex]So, the molecular formula is C2H6.
