Calculate the molar heat of combustion of anthracene

[Specter]

Homework Statement

A 2.56g sample of anthracene, C14H10, was burned to heat an aluminum calorimeter (mass=945 g). The calorimeter contained 1.50 L of water with an initial temperature of 20.5 C and a final temperature of 34.3 C.

a) Calculate the molar heat of combustion of anthracene.

Homework Equations

n=m/M
Q=mcΔt

The Attempt at a Solution

My work:

https://i.imgur.com/WYNiBRD.png

https://i.imgur.com/LNjq3CG.png

Did I do the steps correctly? Did I include the correct sig figs? How would I convert my final answer to J/mol instead of kJ/mol? Thanks! If you need me to type out the work instead of using pictures I can!

 

[mjc123]

Your procedure looks correct (I haven't checked the arithmetic). Your given data are all to 3 sig figs, so your answer should be given to 3 sig figs. (You were right to use more sig figs in the intermediate calculations, but your final answer should be to 3 s.f.)
After getting so much right, you can't convert kJ to J?
PS Thanks for offering to type it out; many people don't and post illegible scribble, but your pictures are very clear and legible.

 

[Borek]

If you need me to type out the work instead of using pictures I can!

That's preferable (check the forum rules) - not only it usually makes things easier to follow, it also makes it possible to quote the solution and mark places were something is wrong.

 

[Specter]

Your procedure looks correct (I haven't checked the arithmetic). Your given data are all to 3 sig figs, so your answer should be given to 3 sig figs. (You were right to use more sig figs in the intermediate calculations, but your final answer should be to 3 s.f.)
After getting so much right, you can't convert kJ to J?
PS Thanks for offering to type it out; many people don't and post illegible scribble, but your pictures are very clear and legible.

Thanks! I ended up figuring out how to convert kJ to J... It was very easy