midterm Q6A

Moderators: Chem_Mod, Chem_Admin

JosephineF
Posts: 49
Joined: Wed Sep 18, 2019 12:17 am

midterm Q6A

Postby JosephineF » Fri Feb 21, 2020 4:14 pm

why is D correct if it is +23 and the given enthalpy is negative? Even when you divide by the number of moles shouldn't it still be negative?

Pegah Nasseri 1K
Posts: 100
Joined: Wed Feb 27, 2019 12:15 am

Re: midterm Q6A

Postby Pegah Nasseri 1K » Fri Feb 21, 2020 7:12 pm

I think you have to pay attention to the wording. The answer choice doesn't specifically state that the enthalpy is positive. It only states that 23.1 kJ of heat will be evolved. The key word used here is "evolved". This word indicates that the heat was released into the surroundings, making the enthalpy negative.

WGaines_2E
Posts: 47
Joined: Mon Nov 18, 2019 12:18 am

Re: midterm Q6A

Postby WGaines_2E » Tue Mar 10, 2020 8:44 pm

since the dH for the reaction is negative, heat would be released when HCL is formed. Evolved would be if the reaction is endothermic


Return to “Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)”

Who is online

Users browsing this forum: No registered users and 1 guest