Answer:
21 kJ
Step-by-step explanation:
The formula for the heat q is
q = mCΔT
Data:
m = 200 g; C = 4.184 J·°C⁻¹g⁻¹
T₁ = 50. °C; T₂ = 25 °C
Calculations:
ΔT = T₂ - T₁
ΔT = 25 – 50.
ΔT = -25 °C
q = 200 × 4.184 × (-25)
q = -21 000 J Convert to kilojoules
q = -21 kJ
The negative sign shows that energy is released, so the water has released 21 kJ of energy.