Question

Ethyl chloride (C2H5Cl), a substance used as a topical anesthetic, is prepared by reaction of ethylene with hydrogen chloride: C2

1)How much PV work is done (in kilojoules), if 84.0 g of ethylene and 130 g of HCl are allowed to react at atmospheric pressure and the volume change is -67.1 L ?

2)What is the value of ΔE (in kilojoules) for the reaction.

3)A reaction is performed in a water bath initially at 23°C which decreases to 15°C by the end of the reaction. For this reaction the sign of heat transfer is ________, and the reaction is classified as ________.

Answer 1

PV work is done (in kilojoules), if 84.0 g of ethylene and 130 g of HCl are allowed to react at atmospheric pressure and the volume change is -67.1 L ?

1 atm = 101.325 kPa

P delta V =1 am * ( -67.1 L )

( -67.1 L )*101.325 x10^-3 KJ

=-6.7989075 Kj

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formula is ΔH = ΔE + ΔnRT

no. of mole of 84.0g of ethylene = 84/((12x2+1x5+35.5)) = 1.3
no. of mole of 130g HCl = 130/(1+35.5) = 3.56

ΔE = 6.79/1.3 = 5.22 kJ/mol

∆H=∆E+P (∆V)

-72.3 kJ = ∆E - 5.2 2

∆E = -67.12 kJ