Question

Iron, at atmospheric pressure, is heated from 60°F to 130°F. Determine the change in specific internal energy of the iron during the process.

Answer 1

Heat capacity of iron Cv = 0.450 J/g- C

Temperature conversion from F to C

C = ( F - 32 ) *5/9

T1 = (60- 32 ) *5/9 = 15.55 C

T2 = ( 130 -32)* 5/9= 56.66 C

Change in specific internal energy deltaU = Cv *(T2 - T1)

Delta U = 0.450 *(56.66- 15.55)

= 18.502 J/g

Internal energy change for iron is the kinetic and vibrational energy of molecules which causes of increasing temperature of iron so its totally dependent upon temperature because kinetics theory of molecules depend upon the temperature.