Question

Calculate the energy released when a 28.9 gram piece of copper is cooled from its melting point of 1083 C to 25.0 c the specific heat of copper is .385 j/g c

Answer 1

`\boxed{\text{11.8 kJ}}`

Step-by-step 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
`\boxed{\textbf{11.8 kJ}}` of energy.