Difference between revisions of "PChem312 f20 w11"

Revision as of 14:37, 26 October 2020

Monday, Oct 26, 2020

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

Sec 4.4

Temperature dependence of reaction enthalpies...

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 C_p,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).

Weds, Oct 28, 2020

DCS?

Thurs, Oct 29th, 2020

Exam 2, Ch 3 and 4.

Friday, Oct 30th, 2020

no class

@@ Line 16: / Line 16: @@
 Study Example Problem 4.2 for calculation details...
 :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]]