Below you can see the chemical reaction I'm working with:

$$\ce{CH_3CH_2OH(l) + 3O_2(g) -> 2CO_2 (g) + 3H_2O(g)}$$

I've got so far: https://i.sstatic.net/3zgNk.png

How can I calculate the volume of the product of carbon dioxide gas (the pressure is 1 bar, and the temperature is 20 deg Celsius).


1 Answer 1

  1. You need to determine the limiting reactant. Use the equation and the number of moles of $\ce{CH_3CH_2OH}$ and $\ce{O_2}$.

    In the reaction, you need 1 mol of $\ce{CH_3CH_2OH}$ and 3 mol of $\ce{O_2}$ to get 2 mol of $\ce{CO_2}$. If you have less than 1 mol of $\ce{CH_3CH_2OH}$ but 3 mol of $\ce{O_2}$, you cannot get 2 mol of $\ce{CO_2}$. In such a case, $\ce{CH_3CH_2OH}$ is the limiting reactant. The amount of $\ce{CO_2}$ will thus be lower than 2 mol.

  2. Using the number of moles of the limiting reactant, you should be able to calculate the number of moles of $\ce{CO_2}$ produced. Use proportions!

  3. The last step will involve using the ideal gas equation, by assuming that $\ce{CO_2}$ behaves like an ideal gas. $$PV=nRT$$

    You have the pressure $P$, the temperature $T$, $n$ (the number of moles of the $\ce{CO_2}$), $R$ is a constant. Find the volume $V$.

  • $\begingroup$ If you'd like to take the time, i would like to know what the exact answer to my question is, i mean - the result. $\endgroup$ Commented May 15, 2013 at 18:32
  • 3
    $\begingroup$ @FrederikWitte You're not trying to use the site to get your homework done, are you? $\endgroup$
    – Jerry
    Commented May 15, 2013 at 18:39
  • $\begingroup$ Just a side note: Pressure is usually referred to with a small $p$. $\endgroup$ Commented Apr 2, 2014 at 2:29
  • $\begingroup$ @Martin It can be represented by both. $\endgroup$
    – Jerry
    Commented Apr 2, 2014 at 4:57
  • $\begingroup$ @Jerry, you are right. IUPAC goldbook suggests a small $p$. $\endgroup$ Commented Apr 2, 2014 at 8:05

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