Thermodynamics of Reactions with Glucose

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Discussion Overview

The discussion revolves around the thermodynamics of reactions involving glucose, specifically focusing on calculating changes in enthalpy (ΔH) at different temperatures. Participants explore methods to approach the problem, including the application of Hess's law and heat capacities.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Technical explanation

Main Points Raised

  • One participant expresses feeling overwhelmed by the problem and seeks guidance on how to account for temperature changes in enthalpy calculations.
  • Another participant suggests that heat capacities may play a role in determining the change in temperature from 298.15 K to 330.15 K.
  • A different participant reports successfully calculating the change in enthalpy at 330.15 K using Hess's law and integrating the change in heat capacity (ΔCp) over the temperature range.
  • One participant notes difficulty in finding examples for similar calculations and mentions challenges in understanding their professor's explanations.
  • Another participant points to specific tables (Table 4.1 and 4.2) as a resource to help get started with the calculations.

Areas of Agreement / Disagreement

Participants do not appear to reach a consensus on the best approach to the problem, and multiple viewpoints regarding the calculation methods and resources remain present.

Contextual Notes

Participants reference specific temperature values and the need for heat capacity data, but there may be limitations in the assumptions made regarding the applicability of these values across different temperatures.

Who May Find This Useful

Students studying thermodynamics, particularly those working on homework related to reaction enthalpies and temperature effects, may find this discussion beneficial.

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Homework Statement


ps4n2.jpg



Homework Equations


ΔH rxn = ΔH products - ΔH reactants
ΔU = q + w


The Attempt at a Solution


Pretty overwhelmed with the entire problem. Since the ΔH's of all reactants and products were in the literature for the reference temperature of 298.15 K, I was able to plug them in and get the value for that temperature. I am not sure how it changes with temperature increase?

Can anyone point me in the right direction?
 
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Perhaps heat capacity(-ies) is the reason where delta T = 298.15 K - 330.15 K.
 
Ah, okay I was able to the the change in enthalpy for 330.15 K by Hess's law, and adding delta H rxn (298.15K) to the integral of delta Cp dT integrated from To to T.

Now I'm stuck on b. part ii. I can't find any examples anywhere on calculating problems like this and my professor is so highly educated (MIT, Harvard, UPenn) that I can't understand him.

Ahh, any help is appreciated!
 
It lies somewhere in Table 4.1 and 4.2. That will get you started.
 

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