4A.13

[Drew Myers 4G]

I’m confused as to how to start this question. It tells you that deltaV=0, so from that I know deltaU = q. Beyond that, I have no idea what to do.

[Aliya Jain 2B]

Since C= q/delta T, you can divide 3.50 kJ by 7.32 K and get C=0.478 kJ/K. From there you can multiply that number with the change of temperature(2.47 kJ) of the calorimeter to find q of the calorimeter. The q of the reaction is the negative value of the q of the calorimeter

[Megan Vu 1J]

Because q = CdeltaT, you are able to solve this equation by first calculating for the C.
C = q/delta T, and thus, it is -3.50 kJ/7.32 K = 0.478 kJ/K^-1. You know that it is negative since the q of a calorimeter is negative since energy is leaving.
Then, you can calculate it again from q(Cal) = Cdelta T to C = -q/delta T = -0.478 kJ / 2.49 K = -1.19 kJ.

This shows the differences between the calorimeter and regular calculation for heat.