Given ; 4.16g of carbon and 0.39g of hydrogen. The atomic weight of carbon is 12.011g/mol and the atomic weight of hydrogen is 1.008g/mol. Use this knowledge to calculate the molecular formula for benzene, what is the chemical formula for benzene????

1 Answer
Ernest Z.
Mar 3, 2018

There is not enough information to determine the molecular formula, but the empirical formula is "CH"CH.

Explanation:

The empirical formula is the simplest whole number molar ratio of the elements in the compound.

We must convert the masses of "C"Cand "H"H to moles and then find the ratio.

"Moles of C" = 4.16 color(red)(cancel(color(black)("g C"))) × "1 mol C"/(12.01 color(red)(cancel(color(black)("g C")))) = "0.3464 mol C"

"Moles of H" = 0.39 color(red)(cancel(color(black)("g H"))) × "1 mol H"/(1.008 color(red)(cancel(color(black)("g Cl")))) = "0.387 mol H"

From this point on, I like to summarize the calculations in a table.

bbul("Element"color(white)(m) "Mass/g"color(white)(m) "Moles"color(white)(m) "Ratio"color(white)(m)"Integers")
color(white)(mm)"C" color(white)(XXXm)4.16 color(white)(Xmll)0.3464 color(white)(Xm)1color(white)(mmmmll)1
color(white)(mm)"H" color(white)(XXXm)0.39 color(white)(mmll)0.387 color(white)(Xml)1.11 color(white)(mmml)1

The molar ratio is "C:H = 1:1".

The empirical formula is "CH".

There is not enough information to determine the molecular formula.

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