The enthalpy changes for the following precesses are listed below :
Cl2(g)→2Cl(g), 242.3 kJmol−1
I2(g)→2I(g), 151.0 kJmol−1
ICl(g)→I(g)+Cl(g), 211.3 kJmol−1
I2(s)→I2(g), 62.76 kJmol−1
Given that the standard states for iodine and chlorine are I2(g) and Cl2(g), the standard enthalpy for the formation of Cl(g) is :