Question

wHAT IS MOLECULAR FORMULA THAT CONSISTS OF 80% CARBON AND 20% HYDROGEN AND HAS MOLAR MASS OF 30.1 GRAM OF MOLEA. CH3B. C4H12C. C3H9D. C2H6

Answer 1

D. C2H6

Step-by-step 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:

`\begin{gathered} 100\%-30.1g \\ 80\%-x=(80\%*30.1g)/(100\%) \\ x=24.08g \end{gathered}`

• Hydrogen:

`\begin{gathered} 100\%-30.1g \\ 20\%-x=(20\%*30.1g)/(100\%) \\ x=6.02g \end{gathered}`

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:

`24.08g*(1mole)/(12.04g)=2`

• Hydrogen:

`6.02g*(1mole)/(1.003g)=6`

So, the molecular formula is C2H6.