[long-live-mercutio]

Hello everyone!
 
This is the equation that describes the temperature dependence of calcium phosphate's heat capacity:
 
С_p = 203,3 + 170,1*10^–3 Т – 26,11*10⁵ Т ^–2 J/(mol*K)
 
in the  273 - 1 373 К temperature interval. What is the ΔH of the heating reaction of calcium phosphate from 600 to 900 K?
 
The answer is 97.8 kJ, but the only answer I can get after integration is

 203.3 (900-600) + (170.1*10^-3/2)(900²-600²)+26.11*10⁵*(1/900-1/600) = 93.460  kJ.

The problem doesn't state the amount of calcium phosphate, so I've been wondering if that's the reason why the answers don't match - should I find the amount of mol, instead of just assuming it's 1 mol? But I can't come up with a way to do so:( Could you help me please?





I have made the calculations again and everything is okay now! Sorry, my bad:)

[Corribus]

Are you sure you did your arithmetic right? I got 97811 J (97.811 kJ) when I used your equation.
(Term 1 ~ 60990 J, Term 2 ~ 38272 J, Term 3 ~ -1451 J)

[long-live-mercutio]

Yes, I have done it again and everything was correct, thank you!