# Calculate the molar heat of combustion of anthracene

• Specter
In summary, a 2.56g sample of anthracene was burned to heat an aluminum calorimeter containing 1.50 L of water. The molar heat of combustion of anthracene was calculated using the equations n=m/M and Q=mcΔt. The given data was all to 3 sig figs, so the final answer should be given to 3 s.f. The conversion from kJ to J can be done easily.
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.

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!

#### Attachments

• WYNiBRD.png
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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.

Specter
Specter said:
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.

mjc123 said:
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

## What is the molar heat of combustion of anthracene?

The molar heat of combustion of anthracene is the amount of energy released when one mole of anthracene is completely burned in excess oxygen under standard conditions.

## How is the molar heat of combustion of anthracene calculated?

The molar heat of combustion of anthracene is calculated by measuring the amount of heat released during the combustion reaction and dividing it by the number of moles of anthracene that were burned.

## What is the significance of calculating the molar heat of combustion of anthracene?

The molar heat of combustion of anthracene is an important physical property that can be used to determine the energy content and efficiency of anthracene as a fuel source.

## What factors can affect the accuracy of the calculated molar heat of combustion of anthracene?

The accuracy of the calculated molar heat of combustion of anthracene can be affected by the purity of the anthracene sample, the completeness of the combustion reaction, and any heat losses during the experiment.

## How does the molar heat of combustion of anthracene compare to other hydrocarbons?

The molar heat of combustion of anthracene is typically lower than other hydrocarbons due to its high carbon content and low hydrogen content. It is also less efficient as a fuel source compared to other hydrocarbons.

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