Difference between revisions of "PChem312 f20 w11"

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Study Example Problem 4.2 for calculation details...
 
Study Example Problem 4.2 for calculation details...
 
:ΔH°(298K) = -92.3 kJ/mol HCl
 
:ΔH°(298K) = -92.3 kJ/mol HCl
: temp correction = -2.8 kJ/mol HCl (''mainly due to the change in the heat capacity of Cl<sub>2</sub> gas.'')
+
: temp correction = -2.8 kJ/mol HCl
 +
:ΔH°(298K) = -95.1 kJ/mol HCl
 +
:'''''Explanation: this difference is mainly due to the change in the heat capacity of Cl<sub>2</sub> gas; the product HCl has a lower heat capacity than Cl<sub>2</sub>...so heat produced from the reaction cannot be contained in the products hence it is given off...ie. higher ΔH°(1450K).'''''
  
 
:[[File:ExProb4_2.png|600px]]
 
:[[File:ExProb4_2.png|600px]]

Revision as of 14:37, 26 October 2020

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Monday, Oct 26, 2020

Announcement: Exam 2, Thursday, Oct 29th (Ch 3 and 4)

Sec 4.4

Temperature dependence of reaction enthalpies...

Screen Shot 2020-10-26 at 7.56.09 AM.png

This problem involves 2 parts:

1) ΔH°(298K) can be calculated via heats of formation (ΔH°f)
2) the second part requires that you look up the Cp,m values from table 2.5...

Study Example Problem 4.2 for calculation details...

ΔH°(298K) = -92.3 kJ/mol HCl
temp correction = -2.8 kJ/mol HCl
ΔH°(298K) = -95.1 kJ/mol HCl
Explanation: this difference is mainly due to the change in the heat capacity of Cl2 gas; the product HCl has a lower heat capacity than Cl2...so heat produced from the reaction cannot be contained in the products hence it is given off...ie. higher ΔH°(1450K).
ExProb4 2.png

Weds, Oct 28, 2020

DCS?

Thurs, Oct 29th, 2020

Exam 2, Ch 3 and 4.

Friday, Oct 30th, 2020

no class