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The chemical in question is L Carvone. It is an ingredient of some flavors. Tastes and smells like spearmint.

What's a good way to estimate its calorific value? If any. I cannot see it as a carb / protein / fat etc.

Does it have a calorific value at all?

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    $\begingroup$ Calorimetry . Or thermochemistry calculations based on tabulated data. As for fat sugars fuels etc. However from a nutritional view point one should know how the metabolism of the specific molecule work. At extreme, a compound can enter the body and either be excreted intact or accumulated intact. $\endgroup$
    – Alchimista
    Oct 27, 2017 at 12:00
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    $\begingroup$ @curious_cat I agree with Alchimista. It probably isn't too hard to obtain an estimate of the energy of a compound (Nando shows some nice ways below), but that's quite different from the amount of energy you would get from eating it, which would likely require a more detailed understanding of human metabolism. $\endgroup$
    – Tyberius ♦
    Oct 28, 2017 at 13:20

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If carvone ($\ce{C10H14O1}$) is digested by the body using oxygen to generate carbon dioxide and water, you can estimate the heat of this chemical reaction:

$$\ce{C10H14O1 + aO2 -> xCO2 + yH2O}$$

After balancing the equation:

$$\ce{C10H14O1 + 13O2 -> 10CO2 + 7H2O}$$

The required enthalpy can be know from the formation heats of each molecule multiplied by the found factors.

A quick estimation

I just did this exercise using computational chemistry (B3LYP/6-31G(d) in Gaussian09) and found the following energies (in kcal/mol):

  • carvone: -291456.0217
  • oxygen: -94322.73333
  • carbon dioxide: -118326.709
  • water: -47947.30569

The change in energy of the reaction is then:

$$\begin{multline}10\times (\pu{-118327kcal/mol})+7\times (\pu{-47947kcal/mol})\\-1\times (\pu{-291456kcal/mol})-13\times (\pu{-94323kcal/mol}) = \pu{-1137 kcal/mol}\end{multline}$$

this is $\pu{-1137 kcal/mol}$ (exothermic, as expected).

Since molecular weight of carvone is $\pu{150.2 g/mol}$, we can convert to $\mathrm{kcal/g}$, the negative value indicates it releases heat:

$$\frac{\pu{-1137 kcal/mol}}{\pu{150.2 g/mol}} = \pu{-7.6 kcal/g}$$

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  • $\begingroup$ Oh god … I would have assumed that someone who has reached the level of calculating with Gaussian had learnt how to use units correctly … To allow me to upvote in peace with myself I have edited your post to do so. $\endgroup$
    – Jan
    Oct 29, 2017 at 2:31
  • $\begingroup$ Also re units: SI units would of course be preferred ;p $\endgroup$
    – Jan
    Oct 29, 2017 at 2:31
  • $\begingroup$ Sorry, this is just my second answer. I haven't learned much about your strict rules yet. Also, I thought calories would be better since its the common units for food energy. Thanks for edits! $\endgroup$
    – Nando
    Oct 29, 2017 at 2:53
  • $\begingroup$ Well yes, the calorie just won’t die any time soon from nutrition tables; that is unfortunately true. No worries, the answer itself was good but you should really make sure each equation including units adds up … Also, you can ping me by adding @Jan if I commented on your question. While SE does implement some auto-pinging mechanism, they may fail. You as the post owner are always pinged. $\endgroup$
    – Jan
    Oct 29, 2017 at 2:55
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    $\begingroup$ @Nando you can include an image from a book so long as you cite where it came from. $\endgroup$
    – Tyberius ♦
    Oct 29, 2017 at 14:38

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