C + 2S rightarrow CS_2; Delta H^o = +117 , kJ | vedclass

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(A) The combustion reaction of $CS_2$ is: $CS_2 + 3O_2 \rightarrow CO_2 + 2SO_2$. According to Hess's Law,the enthalpy of combustion $\Delta H_c^o$ is

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$-1104$

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(A) The combustion reaction of $CS_2$ is: $CS_2 + 3O_2 ightarrow CO_2 + 2SO_2$. According to Hess's Law,the enthalpy of combustion $\Delta H_c^o$ is given by: $\Delta H_c^o = [\Delta H_f^o(CO_2) + 2 	imes \Delta H_f^o(SO_2)] - [\Delta H_f^o(CS_2) + 3 	imes \Delta H_f^o(O_2)]$. Given: $\Delta H_f^o(CO_2) = -393 \, kJ \, mol^{-1}$,$\Delta H_f^o(SO_2) = -297 \, kJ \, mol^{-1}$,$\Delta H_f^o(CS_2) = +117 \, kJ \, mol^{-1}$,and $\Delta H_f^o(O_2) = 0$. Substituting the values: $\Delta H_c^o = [-393 + 2(-297)] - [117 + 3(0)]$. $\Delta H_c^o = [-393 - 594] - 117$. $\Delta H_c^o = -987 - 117 = -1104 \, kJ \, mol^{-1}$.

$C + 2S \rightarrow CS_2$; $\Delta H^o = +117 \, kJ \, mol^{-1}$; $C + O_2 \rightarrow CO_2$; $\Delta H^o = -393 \, kJ \, mol^{-1}$; $S + O_2 \rightarrow SO_2$; $\Delta H^o = -297 \, kJ \, mol^{-1}$. The heat of combustion of $CS_2$ in $kJ \, mol^{-1}$ is:

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