From all those hydrogen and oxygen equations, which one was exothermic? I said H2 going to 2H, because bonds were broken, but that may not be right.
@apactstudent
Wait, sorry, so is that one the correct answer? Since you can’t do it?
Exothermic processes are when bonds form, i think it was the one with O2, did anyone say -795 kJ?
@blandscreenname it was 2O —> O2. You know those weird potential energy vs. internuclear distance graphs? That’s basically an illustration of this equation. When a bond forms between two oxygen atoms, energy is released. This quantity of energy released is the bond energy of the O-O bond in O2.
@blandscreenname When bonds are broken, energy is actually absorbed. It’s when a bond is formed that a energy is released/exothermic.
Also, did you guys get total energy for the question that asked which did not vary with temperature?
Hey, what do you guys think the curve is gonna be? Do you think -3 (raw score of 81) would be enough to get an 800 on this test?
Also, which reaction was the exothermic reaction?
@allista density didn’t vary with temperature. According to Charles’ Law, temperature and volume are directly proportional. Usually, when the temperature increases, the volume occupied by the gas is larger. However, it said that the gas was held at constant volume, so density cannot change either way (unless more gas is added). I caught it at the last second :S
@tina23 yes, it was the correct answer since it was not proper lab technique
Allista I said density
Wow. I really failed this test. I am giving up on standardized testing.
Did you guy say -795kJ for the one question with the reaction and the delta H’s, which asked to find the overall enthalpy or something like that.
2O—>O2 diatomic was exothermic
@Marshmallow99
I said -555KJ, but that sounds more correct
@Mango920452 Yea
Could someone please post a possible curve? I feel like this test will have an average curve.
@salt123 Wasn’t it 2H -> H2? I remember it was hydrogen that was forming the bonds.
@apactstudent
OMG YAS thank god!!!
Thank you!!
Do you guys think -5 will be an 800? Does chem have a generous curve?
@marshmallow I thought it said H2–>2H
@salt123 That’s what I remember seeing it as.
Yeah, that is correct. it was H2 goes to 2H