Question

The following information is given for aluminum at 1 atm: Ti = 2467.00°C AHvap (2467.00°C) = 1.053 x 104 J/g AHfus (660.00°C) = 398.4 J/g Tm = 660.00°C Specific heat solid = 0.9000 J/g °C Specific heat liquid = 1.088 J/g °C A 44.60 g sample of solid aluminum is initially at 643.00°C. If the sample is heated at constant pressure (P= 1 atm), kJ of heat are needed to raise the temperature of the sample to 877.00°C.

Answer 1

Ti = 643.0 oC
Tf = 877.0 oC
here
Cs = 0.9 J/g.oC

Heat required to convert solid from 643.0 oC to 660.0 oC
Q1 = m*Cs*(Tf-Ti)
= 44.6 g * 0.9 J/g.oC *(660-643) oC
= 682.38 J

Hf = 398.4 J/g

Heat required to convert solid to liquid at 660.0 oC
Q2 = m*Hf
= 44.6g *398.4 J/g
= 17768.64 J

Cl = 1.088 J/g.oC

Heat required to convert liquid from 660.0 oC to 877.0 oC
Q3 = m*Cl*(Tf-Ti)
= 44.6 g * 1.088 J/g.oC *(877-660) oC
= 10529.8816 J

Total heat required = Q1 + Q2 + Q3
= 682.38 J + 17768.64 J + 10529.8816 J
= 28981 J
= 28.981 KJ
Answer: 28.981 KJ