For the equation q=cΔt, q=100KJ, initial temp=20 degrees celsius, final temp=31.4 degrees celsius and I need to find c. Do I need to convert the q value from KJ to J?

Answer 1

convering, depends on the units you want.

c=q/deltaT=100kj/11.3 C= 8.85kJ/C

and

c= 8850J/C

you have to specify units, and both answers are correct.