Ethyl chloride (C2H5Cl), is prepared by reaction of ethylene with hydrogen chloride :
C2H4(g)+HCl(g)→C2H5Cl(g) ΔH=−72.3kJ. What is the value of ΔE (in KJ), if 70g of ethylene and 73g of HCl are allowed to react at 300K?