System vs. Surroundings

[Ethan Mai 1D]

In new today's lecture, the example given listed "heat given off by the reaction" as equal to a negative value, but I am having a little bit of trouble understanding phrasing. Should this value be positive instead, since the term calls for heat being released or loss? How would the value be different if it asked for heat absorbed by the system?

[Nicole Weinstein 3E]

Heat absorbed by the system would be postive. Think of the system, not the surroundings, as the main focus here. If the system releases/loses heat, that would be a negative enthalpy value. If heat is absorbed, that is a gain of heat for the system for enthalpy is postive.

[Mariko Hashimoto 2I]

Nicole is exactly right, you should view the system (where the reaction is taking place) and the surroundings (everything that doesn't include the reaction) as two separate things. The heat given off by the reaction in the lecture was negative, since we were focused on the system (which was losing heat). This qp value would be positive for the surroundings since it was gaining heat.

[Kaira Shibata 1E]

In this case, we are considering the system and the surroundings two different things. When you think about the system, it is giving off the heat (hence the negative value). If you think about it the other way around, the surroundings are absorbing heat and therefore it is a positive value.

[Rebekah Jung 1C]

When considering the system vs the surroundings, absorbing heat would mean a positive value whereas losing/releasing heat would be a negative value. The amount of heat released by a system (-) would result in that same amount of heat being absorbed by the surroundings (+).