Answer
14.4 KJ/^C
Work Step by Step
You are told that the heat for the reaction is 15.57KJ , there are 3.5 g of glucose and that the temperature changed from 20.94 c to 24.72 c.
first work out DeltaT 24.72-20.94 = 3.77 degrees Celsius
then to workout the heat capacity you divide the heat of the reaction by the change in time.
so 15.57/3.77= 4.13 KJ/g.c
but you have 3.5 grams of glucose
so 3.5 X 4.13=14.4 KJ/C
