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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: xpressmusic on May 05, 2011, 12:40:39 PM

Title: Bond breaking and bond forming :(
Post by: xpressmusic on May 05, 2011, 12:40:39 PM

Hi, plz help me solving this... ive tried but useless... :(

here's an equation ...

C40 H82 ------> C16 H34   +   2C12H24

considering bonds broken and formed ONLY, what's the enthalpy change of this reaction ???

Title: Re: Bond breaking and bond forming :(
Post by: sjb on May 05, 2011, 04:43:12 PM

Quote from: xpressmusic on May 05, 2011, 12:40:39 PM

Hi, plz help me solving this... ive tried but useless... :(

here's an equation ...

C40 H82 ------> C16 H34   +   2C12H24

considering bonds broken and formed ONLY, what's the enthalpy change of this reaction ???

What sort of level are you asking the question at? Are you aware of the differences, for instance between primary, secondary, tertiary and quaternary carbons? What do you know of degrees of unsaturation?

Title: Re: Bond breaking and bond forming :(
Post by: Vidya on May 05, 2011, 10:13:18 PM

You need to calculate the degree of unsaturation

then count how many c-c or c=c or C-H bonds are broken or formed .Bond breaking is endo and bond formation is exo.
So take care of the signs also.

Title: Re: Bond breaking and bond forming :(
Post by: xpressmusic on May 21, 2011, 02:38:54 AM

That is what I am asking how do I calculate how many bonds broken or formed...could you please help me further :)

Title: Re: Bond breaking and bond forming :(
Post by: sjb on May 21, 2011, 02:44:39 AM

Quote from: xpressmusic on May 21, 2011, 02:38:54 AM

That is what I am asking how do I calculate how many bonds broken or formed...could you please help me further :)

What is the valency of hydrogen, and of carbon?