AIEEE 2006

In Langmuir’s model of adsorption of a gas on a solid surface

The standard enthalpy of formation \(\Delta _fH^o\) at 298 K for methane, CH4(g), is –74.8 kJ mol–1. The additional information required to determine the average energy for C – H bond formation would be :

(\(\Delta H - \Delta U\)) for the formation of carbon monoxide (CO) from its elements at 298 K is : (R = 8.314 J K–1 mol–1)

The enthalpy changes for the following processes are listed below :
Cl2(g) = 2Cl(g), 242.3 kJ mol–1
I2(g) = 2I(g), 151.0 kJ mol–1
ICl(g) = I(g) + Cl(g), 211.3 kJ mol–1
I2(s) = I2(g), 62.76 kJ mol–1
Given that the standard states for iod...

An ideal gas is allowed to expand both reversibly and irreversibly in an isolated system. If Ti is the
initial temperature and Tf is the final temperature, which of the following statements is correct?