How do I get the calorimetry constant from lab data?

Question

https://i.stack.imgur.com/QjzTv.jpg 

 

Constant should be around 30-85, i know it's mass x specific heat x delta t + mass x specific heat x delta t = 0 but I don't know how to make my equation from my data. Please help.

Answer 1

I'll do one trial, you can do the others, and take an average.

Heat lost by hot water = q = mC∆T = (50 g)(4.184 J/g/deg)(26.4 deg) = 5522.9 J

Heat gained by cold water = q = mC∆T = (50 g)(4.184 J/g/deg)(26 deg) = 5439.2 J

The difference would be the heat absorbed by the calorimeter.  This is 5522.9 - 5439.2 = 83.7 J

The calorimeter constant would thus be 83.7 J/26 deg = 3.22 J/deg

NOTE: the ∆T for hot and cold is almost the same (26.4 v. 26), so little heat was lost to the calorimeter. This is unusual. You estimated value of 30-85 would be the joules, but the cal constant is J/degree, so the answer here would be 3.22 J/deg.