chemistry question help?
What energy in kJ is required to break 2.84 mol of NH3 into atoms? As noted below, this information can be used to calculate ΔH for gas-phase reactions.
- Your name hereLv 48 years agoFavorite Answer
You need a table of bond energies to do this. There's probably one in your book that you're supposed to use. I'll be using this one to solve your problem:
It can be helpful to draw the structure to see exactly which bonds you're breaking. This one is pretty simple, you can easily tell that you're breaking 3 N-H bonds.
So look at the Bond Energy table. You'll see that the energy required to break 1 mole of N-H bonds is 391 kJ.
We have 2.84 moles. If the energy is 391 k per mol, we have to multiply by the number of moles. We also have 3 bonds, not just one. So we also need to multiply by 3.
(391kJ)(2.84)(3) = 3330 kJ
**that answer has already been rounded according to significant figures