Answer:
[tex]\boxed{\text{11.8 kJ}}[/tex]
Explanation:
The formula for the heat released is
q = mCΔT
Data:
m = 28.9 g
C = 0.385 J·°C⁻¹g⁻¹
T₁ = 1083 °C
T₂ = 25.0 °C
Calculations:
(a)Temperature change
ΔT = T₂ - T₁ = 25.0 - 1083 = -1058 °C
(b) Heat released
q = 28.9 × 0.385 × (-1058) = -11 800 J = -11.8 kJ
The negative sign shows that energy is released, so the copper has released [tex]\boxed{\textbf{11.8 kJ}}[/tex] of energy.