simple chem help! please?

Question

Determine the structure of Benzene, and important organic compound, proved to be a difficult challenge for chemists in the 19th century. A sample of benzene was analyzed and found to consist of 1.43g of carbon and 0.119g of hydrogen. Given that the molar mass of benzene is 78.0g, determine both the empirical formula and the molecular formula for benzene.

Answer 1

Benzene is a 6 sided ring with 3 double bonds. The double bonds cannot be next to each other, so they go on every other side. Benzene is composed of 6 carbons and then hydrogens spaced around the ring to give carbon 4 bonds. Hope this helps!

Answer 2

to find the empirical formula, first of all you have to find the ratio between carbon and hidrogen:

step 1
find the number of mole

mole of C= 1.43g/12
= 0.119 mol
mole of H= 0.119g/1
= 0.119 mol

step 2
find the ratio between C and H

for C = 0.119 mol/0.119
= 1
for H = 0.119 mol/0.119
= 1
so,

(CH)n = 78 g/mol
12n + n = 78
13n =78
n = 78/13
= 6

the empirical formula for benzene is (CH)6 and the molecular formula is C6H6.

Answer 3

Divide each mass by the Ar of that element, and you should find equal numbers of moles. This is because the empirical formula is CH. Next, work out how many 13s there are in 78, and you're away!