# Tag Info

$\ ΔH_{sub}(I_2,s)$ can be interpreted as the change in enthalpy when one mole of solid $\ I_2$ converts to gaseous $\ I_2$ at a constant temperature. So the answer should be reaction (b).
The '|' in $\ce{Pd|BaSO4}$ implies that the reaction is taking place in the presence of $\ce{Pd}$ as a metal catalyst. This metal provides surface area for reaction to occur. Also '/' in $\ce{Cr2O3-Al2O3/Mn2O3}$ means that $\ce{Cr2O3}$ can be used in combination with either $\ce{Al2O3}$ or $\ce{Mn2O3}$.