[khatur]

Hi, I got this chemistry assignment where we are given the evidence that Kekule knew when he came up with his structure and we have to explain why the model aligns with the evidence. Here's the evidence:
1. Percent composition indicated the formula for benzene is C6H6.
2. The molecules are non-polar.
3. Melting point was 5.5 C and boiling points was 80.1
4. When a side chain was added, there is only 1 isomer
5. When 2 side chains were added, there is only 3 isomers

 I'm having trouble with the first piece of evidence. How would the percent composition indicate the molecular formula of benzene? And what is percent composition exactly?

[AWK]

1. Percent composition indicated the formula for benzene is C6H6.

This is wrong statement. Percent composition indicate empirical formula CH. This joined with molecular weight 78 obtained by other method gives molecular formula C₆H₆.

[Vidya]

Hi, I got this chemistry assignment where we are given the evidence that Kekule knew when he came up with his structure and we have to explain why the model aligns with the evidence. Here's the evidence:
1. Percent composition indicated the formula for benzene is C6H6.
2. The molecules are non-polar.
3. Melting point was 5.5 C and boiling points was 80.1
4. When a side chain was added, there is only 1 isomer
5. When 2 side chains were added, there is only 3 isomers

 I'm having trouble with the first piece of evidence. How would the percent composition indicate the molecular formula of benzene? And what is percent composition exactly?

There are experiments to know % composition  of carbon and hydrogen in the given sample and then empirical formula