question_answer

\[\Delta {{G}^{o}}vs\,\,T\]plot in the Ellinghams diagram slopes downwards for the reactions

A) \[Mg+\frac{1}{2}{{O}_{2}}\xrightarrow{{}}MgO\]

B) \[2Ag+\frac{1}{2}{{O}_{2}}\xrightarrow{{}}A{{g}_{2}}O\]

C) \[CO+\frac{1}{2}{{O}_{2}}\xrightarrow{{}}C{{O}_{2}}\]

D)  All of the above

Correct Answer: D

Solution :

Reaction (i)\[M(s)+\frac{1}{2}{{O}_{2}}\xrightarrow{{}}MO(s)\]                 [where,\[M=\]highly reactive metal] Reaction (ii)\[CO(g)+\frac{1}{2}{{O}_{2}}\xrightarrow{{}}C{{O}_{2}}(g)\] Reaction (iii)\[C(s)+\frac{1}{2}{{O}_{2}}(g)\xrightarrow{{}}C{{O}_{2}}(g)\] \[\Delta {{G}^{o}}\,\,vs\,\,T\]plot in the Ellinghams diagram slopes downwards for the reaction (I) and reaction (II). For reaction (III)\[\Delta {{G}^{o}}\,\,vs\,\,T\]in the diagram slopes upwards.