How much heat is given out when a piece of iron of mass 50g and specific heat capacity 460 Jkg−¹k−¹ cools from 85°C to 25°C?

A. 1.38 x 10^6 J
B. 2.53×10^4J
C. 7.66×10³J
D. 1.38×10³J
E. 1.27 X10³J

Correct Answer:

Option D – 1.38×10³J

Explanation

Q = mcΔθ = 0.050 x 460 x (85 – 25) = 1.38×10³J