An iron piston in a compressor has a mass of 3.62 kg. If the specific heat of iron is 0.449 J/g°C, how much heat is required to raise the temperature of the piston from 12.0°C to 111.0°C?

I got Q=3620(4.184)(99) which equals 160.91 but the answer is 1.61x10^5. Where did I go wrong?

1 Answer
Dec 5, 2017

DeltaE=1.61*10^5J

Explanation:

DeltaE=mcDeltatheta, where:

  • DeltaE = change in energy (J)
  • m = mass of the object (kg)
  • c = specific heat capacity of the object (J kg^(-1) K^(-1))
  • Deltatheta = change in temperature (K)

0.449J g^(-1) ""^circC^(-1) = 449J kg^(-1) K^(-1)

Deltatheta = 111-12=99^circC

As Delta""^circC=DeltaK

Deltatheta=99K

DeltaE=3.62*449*99=160912.62J=1.6091262*10^5J~~1.61*10^5J