The standard gibbs free energy of formation of is zero. (a) al (s) (b) br2 (l) (c) hg (l)

(a), (b) and (c)

Explanation:

The standard Gibbs free energy of formation of a compound is defined as the change of Gibbs free energy that occurs in the formation of 1 mole of a substance from its component elements in their standard states.

Based on this definition, elements in their standard state have a standard free energy of formation of zero.

Standard state of aluminium is Al(s), of bromine is Br₂(l) and for mercury is Hg(l). That means the free energy of formation is zero for (a), (b) and c.

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