Answer:
= - 26.31 kJ
Explanation:
we know that number of moles is calculated as
[tex]Moles of C_{12}H_{22}O_{11} = \frac{mass}{molecular\ weight}[/tex]
[tex] = \frac{(1.631 g)}{(342.29 g/mol)}[/tex]
= 0.00476 mol
Heat absorbed by calorimeter [tex]= heat\ capacity \times temperature\ rise[/tex]
[tex]= 5.30 kJ/°C x (27.75 - 22.68)°C[/tex]
= 26.87 kJ
Enthalpy of combustion
[tex]\Delta Hc = \frac{- 26.87}{0.00486}[/tex]
= - 55290.12 kJ/mol
Negative sign shows that the heat is released
The balanced reaction
[tex]C_{12}H_{22} O_{11}(s) + 12 O_2(g) = 12 CO_2(g) + 11 H_2O(l)[/tex]
ΔHc = ΔU + Δng (RT)
-55290.12 = ΔU + (12 - 12) *(RT)
[tex]\Delta U = - 55290.12 kJ/mol \times 0.00476 mol[/tex]
= - 26.31 kJ
