Question

calculate the number of Kilojoules to warm 125 g of iron from 23.5 C to 78.0 C

Answer 1

the answer is 2.9975

Answer 2

We know that
M = 125 g = 125/1000 kg = 0.125 kg,
θ₂ = 78.0°C
θ₁ = 23.5°C ,
c = 0.44kJ/kg°C,

the number of Kilojoules to warm the iron would be

Q = mc(θ₂ - θ₁)

Q = 0.125*0.440*(78 - 23.5)

Q  =  2.9975 kJ 

2.9975 kJ required to warm it.