how do you work this problem?

To solve this question, use the q=mcΔt formula. Here, m=83g, c=4.18 J/(g*K). Δt is found by Tfinal-Tinitial, which is 129-(-18)=147 degrees C. Since the conversion from C to K is only adding 273 to the C, the difference in degrees C is equivalent to degrees K. So:

q=(83g)*(4.18 J/g*K)*(147K)=

**51000.18J=51kJ**