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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: ty on October 09, 2009, 04:00:41 PM

Title: Empirical Formula giving me too much trouble. >:(
Post by: ty on October 09, 2009, 04:00:41 PM

"A 0.4791 -g sample was analyzed and was found to contain the following elements:

Carbon: 0.1929 g
Hydrogen: 0.01079 g
Oxygen: 0.085 g
Chlorine: 0.1898 g"

After I finish the whole thing, I come up with:

C = 0.015
H = 0.01
O = 0.005
Cl = 0.005

Is this correct?

Title: Re: Empirical Formula giving me too much trouble. >:(
Post by: ty on October 09, 2009, 04:05:14 PM

Rephrasing my question: How do I write those answers out into an empirical formula?

Title: Re: Empirical Formula giving me too much trouble. >:(
Post by: Borek on October 09, 2009, 04:13:33 PM

You have to convert these to the smallest integers keeping the ratios between numbers. Ususally good starting point is to divide all buy the smallest number - the smallest then becomes 1, with some luck others will be integers too. If not - you have to try to multiply them all by 2 or 3 or something like that. This is mostly trial and error.

In your case all numbers are very obvious multiplies of a common small number.

Title: Re: Empirical Formula giving me too much trouble. >:(
Post by: ty on October 09, 2009, 04:14:51 PM

Oh yeah.. Geez, I wasn't even thinking. I forgot that step altogether. It's been an off day.

Thank you.