X , g of ethanol (CH_3CHO) is burnt in a bomb | vedclass

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(C) The combustion reaction is: $CH_3CHO_{(l)} + \frac{5}{2}O_{2(g)} 	o 2CO_{2(g)} + 2H_2O_{(l)}$The molar mass of $CH_3CHO$ is $12 	imes 2 + 1 	im

Vedclass · Accepted Answer

$\Delta U_{	ext{combustion}} = -\frac{44Y}{X} \, J \, mol^{-1}$

Vedclass · Answer

(C) The combustion reaction is: $CH_3CHO_{(l)} + \frac{5}{2}O_{2(g)} 	o 2CO_{2(g)} + 2H_2O_{(l)}$The molar mass of $CH_3CHO$ is $12 	imes 2 + 1 	imes 4 + 16 = 44 \, g \, mol^{-1}$.Given that $X \, g$ of $CH_3CHO$ produces $Y \, J$ of heat,the heat produced by $1 \, g$ is $\frac{Y}{X} \, J$.Therefore,the heat produced by $44 \, g$ (which is $1 \, mol$) of $CH_3CHO$ is $\frac{44Y}{X} \, J \, mol^{-1}$.$A$ bomb calorimeter measures the change in internal energy at constant volume,denoted as $\Delta U$ or $\Delta E$.Since heat is released (exothermic),the change in internal energy is negative: $\Delta U_{	ext{combustion}} = -\frac{44Y}{X} \, J \, mol^{-1}$.

$X \, g$ of ethanol $(CH_3CHO)$ is burnt in a bomb calorimeter and $Y \, J$ of heat is produced. Then,which of the following is correct for the enthalpy of combustion?

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