Heat Capacity

Examples

Problem: You have a burner that emits 15,000 J of heat in the period that it is left on. Will this burner be able to raise 2 kg of water from 50 °C to 52 °C? The specific heat capacity of water is 4,186 J/kg °C.

Solution: Use Q=mCΔT. The amount of heat needed to do the process specified in the question is Q=(2 kg)*(4,186 J/kg °C)*(2 °C)=16,744 J. Since the burner only gives of 15,000 J, the water will not reach the desired temperature.

Problem: What is the specific heat of 3 g substance that takes 100 J to raise 3 degrees.

Solution: Use Q=mCΔT. Q=100 J, m= 3 g, ΔT=3 °C. 100J= (3 g)*(C)*(3 °C). C=11.11111 J/g °C.

References

• http://chemwiki.ucdavis.edu/Physical_Chemistry/Thermodynamics/Calorimetry/Heat_Capacity
• http://www.chm.davidson.edu/vce/calorimetry/heatcapacity.html
• http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/spht.html