[mudkip26]

A 2 g sample of lauric acid (C12H24O2), a common constituent of fats, is burned in a bomb calorimeter. The temperature of the calorimeter increases by 51.2oC (Celsius). Given that the energy of combustion (E) for lauric is -37.1 kJ/g, calculate the heat capacity of the bomb calorimeter. Make sure you enter kJ/C for your unit behind the number.

My answer: -.362kJ/C

What am I doing wrong?

[Borek]

How are we going to know what you did wrong if we don't know what you did? Show your work, not just the result, and we will can be able to comment.

[mudkip26]

How are we going to know what you did wrong if we don't know what you did? Show your work, not just the result, and we will can be able to comment.

I'm sorry.
I used the equation ΔE=mcΔT.
So,

-37.1=(2g)(51.2)(c)
so....
(-37.1)/(102.4)=c
I keep getting -.362

Where am I going wrong?

[Sophia7X]

If you calculate the constant using that equation, your units for C is kJ/°C*g. But the units for the bomb calorimeter constant is kJ/°C.

That equation is not applicable to bomb calorimetry.
Hint: use q = cΔT instead, and remember, the energy of combustion is -37.1 kJ PER gram. You have 2 grams. How much energy is released?

[mudkip26]

If you calculate the constant using that equation, your units for C is kJ/°C*g. But the units for the bomb calorimeter constant is kJ/°C.

That equation is not applicable to bomb calorimetry.
Hint: use q = cΔT instead, and remember, the energy of combustion is -37.1 kJ PER gram. You have 2 grams. How much energy is released?

That makes much more sense. Thank you (:
So I would take -37.1x2 and that would be my q value?

[Sophia7X]

Yep, you got it!

[mudkip26]

Yep, you got it!

Awesome! Thanks for your *delete me* (:
One more thing. My delta T is just 51.2 right?

[Sophia7X]

Yeah.


Also, heat capacity is a positive constant so do the calculation with a positive q.

[mudkip26]

Yeah.


Also, heat capacity is a positive constant so do the calculation with a positive q.

Ahhhh! Thank you! (:
Would you be able to take a look at my other topic?

[Sophia7X]

I think I already did, lol.

[mudkip26]

I think I already did, lol.

Ahhhh, okay. (:
Any help would be appreciated, though.