CHEMISTRY COMMUNITY

On the test where we were supposed to state the First Law of Thermodynamics, how specific were we supposed to get with the definition?

Thanks!

I put that the First Law of Thermodynamics states that the internal energy of an isolated system will not change. I also put just in case. Hopefully that's specific enough.

The first law of thermodynamics is essentially the law of conservation of mass: matter is neither created nor destroyed. However it is super important to know that as stated by the first law of thermodynamics, the total energy of an isolated system is constant

I said that energy cannot be created or destroyed, so i think if you said something along those lines you'll be fine. I also put the equation deltaU = q + w

I also put the equation (delta)E(univ)= (delta)E(sys) + (delta)E(surroundings), but I'm not sure if that was redundant in lieu of stating that matter and energy are neither created nor destroyed.

The question was pretty vague so I was also wondering how specific we were supposed to be because all I answered was that "Energy can't be created or destroyed, conservation of energy."

I just wrote the equation, delta U = q + w.

Along with the equation, I also just stated that energy can neither be created nor destroyed, just transferred in various forms.

I stated that energy cannot be created nor destroyed, only transferred. I'm pretty sure that is all they would be looking for, because the First Law of Conservation is primarily concerned with the conservation of energy.

The textbook says the first law of thermodynamics is that the internal energy of an isolated system is constant, so I think that would be sufficient.

Ramya Lakkaraju 1B wrote:I just wrote the equation, delta U = q + w.

I also just wrote this equation. I honestly didn't even think to do any explaining. Hopefully that was sufficient!

Yeah, I basically just put "energy can be neither created nor destroyed, only conserved." My TA told me that as long as you understood the concept, they didn't dock you for not being 100% accurate.

Energy can not be created nor destroyed

I also wrote that the internal energy of an isolated system remains constant.

Conservation of energy in the universe.

(I didn't even think of elaborating...)

Kyung_Jin_Kim_1H wrote:Conservation of energy in the universe.

(I didn't even think of elaborating...)

Same.

They accepted multiple answers. Mine was "energy cannot be created or destroyed; it must be exchanged."