Respuesta :
Answer : The enthalpy of the following reaction is, -390.3 KJ
Explanation :
The given balanced chemical reactions are,
(1) [tex]C(s)+2H_2(g)\rightarrow CH_4(g)[/tex] [tex]\Delta H_1=-74.6KJ/mole[/tex]
(2) [tex]C(s)+2Cl_2(g)\rightarrow CCl_4(g)[/tex] [tex]\Delta H_2=-95.7KJ/mole[/tex]
(3) [tex]H_2(g)+Cl_2(g)\rightarrow 2HCl(g)[/tex] [tex]\Delta H_3=-184.6KJ/mole[/tex]
The final reaction of is,
[tex]CH_4(g)+4Cl_2(g)\rightarrow CCl_4(g)+4HCl(g)[/tex] [tex]\Delta H_{rxn}=?[/tex]
Now adding reaction 2 and twice of reaction 3 and reverse of reaction 1, we get the enthalpy of of the reaction.
The expression for enthalpy for the following reaction will be,
[tex]\Delta H_{rxn}=[2\times \Delta H_3]+[-1\times \Delta H_1]+[1\times \Delta H_2][/tex]
where,
n = number of moles
Now put all the given values in the above expression, we get:
[tex]\Delta H_{rxn}=[2mole\times (-184.6KJ/mole)]+[-1mole\times (-74.6KJ/mole)]+[1\times (-95.7KJ/mole)]=-390.3KJ[/tex]
Therefore, the enthalpy of the following reaction is, -390.3 KJ
Answer:
-390.3 KJ
Explanation:
For Hess's Law, we need to get the corresponding equation below using the sequence of reactions given
By manipulating the reaction, either reversing them or multiplying/dividing them to a certain factor, we can get to the target equation as well as the total enthalpy
CH4(g) + 4Cl2(g) → CCl4(g) + 4HCl(g)
C(s) + 2H2(g) → CH4(g) ΔH = −74.6kJ (needs to reverse)
C(s) + 2Cl2(g) → CCl4(g) ΔH = −95.7kJ (retain)
H2(g) + Cl2(g) → 2HCl(g) ΔH = −184.6kJ (multiply by 2 to get 4Cl2 and cancel out 4 HCl and 4 H2)
Therefore, it is -390.3 KJ
