The heat Q absorbed by a sample with mass m of a material with specific heat c that increases its temperature by ΔT is:
[tex]Q=mc\Delta T[/tex]Find the change in temperature of the sample by subtracting the initial temperature from the final temperature:
[tex]\Delta T=T_f-T_0=100.0ºC-76.0ºC=24.0ºC[/tex]Replace m=1230g, c=4.68J/gºC and ΔT=24.0ºC to find the amount of heat added to the Lead:
[tex]Q=(1230g)(4.68\frac{J}{gºC})(24.0ºC)=138,153.6J\approx138kJ[/tex]Therefore, the amount of heat added to the Lead was approximately 138kJ.