Respuesta :
Answer:
[tex]\Delta E_{rxn}[/tex] for combustion of naphthalene is -5164 kJ/mol
Explanation:
[tex]\Delta E_{rxn}=C_{calorimeter}\times \Delta T_{calorimeter}[/tex]
where, C refers heat capacity and [tex]\Delta T[/tex] refers change in temperature.
Here, [tex]\Delta T_{calorimeter}=(32.33-24.25)^{0}\textrm{C}=8.08^{0}\textrm{C}[/tex]
So, [tex]\Delta E_{rxn}=(5.11\frac{kJ}{^{0}\textrm{C}})\times (8.08^{0}\textrm{C})=41.3kJ[/tex]
[tex]\Delta E_{rxn}[/tex] is generally expressed in terms of per mole unit of reactant. Also, [tex]\Delta E_{rxn}[/tex] should be negative as it is an exothermic reaction (temperature increases).
Molar mass of naphthalene is 128.17 g/mol
So, 1.025 g of naphthalene = [tex]\frac{1.025}{128.17}moles[/tex] of naphthalene
= 0.007997 moles of naphthalene
[tex]\Delta E_{rxn}=-\frac{41.3kJ}{0.007997mol}=-5164kJ/mol[/tex]
