Ethyl chloride (C2H5Cl), a substance used as a topical anesthetic, is prepared by reaction of ethylene with hydrogen chloride:
C2H4(g)+HCl(g)→C2H5Cl(g)
ΔH∘ = -72.3 kJ.
1. How much PV work is done (in kilojoules), if 90.0g of ethylene and 130g of HCl are allowed to react at atmospheric pressure and the volume change is -71.9L ?
2. What is the value of ΔE (in kilojoules) for the reaction?
Thermochemistry Problems
2013-10-25 12:49 am
回答 (1)
2013-10-25 1:29 am
✔ 最佳答案
1. w = -∫P∆V= -P∆V
= -(101.325 kPa)(71.9/1000)m³ = 7.29kJ
2. no. of mole of 90.0g of ethylene = 90/(12x2+1x5+35.5) = 1.40
no. of mole of 130g HCl = 130/(1+35.5) = 3.56
ΔE = 7.29/1.4 = 5.2 kJ/mol
2013-10-24 17:32:01 補充：
Since there is volume contraction. The PV work done is to the system.
Energy of the system increases. So, w>0 and ΔE>0
2013-10-25 01:47:38 補充：
Sorry!
∆H=∆E+P (∆V)
-72.3 kJ = ∆E - 5.2
∆E = -67.1 kJ
收錄日期: 2021-04-13 19:46:56
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