[Mrock4]

Hello everybody! I'm taking an Introductory class in chemistry for no credit, in order to prepare myself for the pre-med program at my university. This class is online. Anyways, my instructor gave me an equation to balance in the first day of class, as some extra practice since I have a great interest in chemistry, although I never took it in high school.

The issue now, the instructor gave me an equation, I balanced it (or so I thought), and even ran the equation through a calculator online- which came up with the same results. Unfortunately, the instructor says I'm incorrect. I just wanted a second opinion. If I'm counting the atoms wrong, please let me know..

I was told to balance:
C6H5COOH + O2 = CO2 + H2O

I came up with:
2C6H5COOH + 15O2 = 14CO2 + 6H20

My logic in counting the atoms was this (I'll only do the left)

C: There's 14 C on the left. I got this by taking the coefficient (2) times C6, which equals 12 C, then 2 times the second Carbon, which equals 2. Therefore, 14 C.

O: There is two Oxygen atoms on the "COOH" part, times the coefficient, equals 4 O. Then 15 O2 = 30 O, so I figure there is 34 O.

H: There's 2 (coefficient again) times H5 = 10 H. Then 2 times the second hydrogen in the statement, so that's 12 H.

On the right side, I figure there is 34 O, because 14CO2 (14 x O2 = 28 O, then 6 x O on the 6H20 part). etc..that's pretty much the logic I used to achieve these numbers.

The instructor says the following:
I count 32 O on the left and 34 on the right.
13 C on the left and 14 C on the right
Only H is balanced.

Her answer:
2 C7H6O2 +15 O2 => 14CO2 + 6 H2O

Any thoughts? I don't mind if I am doing it wrong, but I just want to be sure, because I THOUGHT I understood what I was doing, but I'm not sure at all now. I just want to build a solid foundation before I get too deep into this stuff. Thanks in advance everybody!

[Danial]

Yours and hers look the same to me
She just simplified the formula a little
She just clustered in the extra C, O, and H to make it smaller

Is that what you mean?

[Mrock4]

Yours and hers look the same to me
She just simplified the formula a little
She just clustered in the extra C, O, and H to make it smaller

Is that what you mean?

Thanks. Yeah, that's pretty much all I was wondering. To me, it looked like both were balanced, just differently. However, her response was "that is close, but incorrect"..just was hoping other eyes could reassure me that I'm on the right track.

[Danial]

Oh that's weird,
That's exactly how I would of done it

[Borek]

Sorry to say that, but if she doesn't see both equations are OK and correctly balanced she should not teach. C6H5COOH is a semistructural formula of benzoic acid, C7H6O2 is a molecular formula. Unless you are specifically told to use (not use) one of these it is perfectly OK to use whichever suits you best.