Which would not have a heat of formation of 0 kJ/mol?   Group of answer choicesF2(g)H2(g)S2(g)Kr(g)

The heat of formation is defined as the heat absorbed or released when one mole of a substance is formed from its elements in their standard states. The standard state of an element is its most stable state at 1 atm and 25°C.

1. F2(g): This is the standard state of Fluorine. So, its heat of formation is 0 kJ/mol.
2. H2(g): This is the standard state of Hydrogen. So, its heat of formation is 0 kJ/mol.
3. Kr(g): This is the standard state of Krypton. So, its heat of formation is 0 kJ/mol.

However,

4. S2(g): This is not the standard state of Sulfur. The standard state of sulfur is S8(s). So, its heat of formation is not 0 kJ/mol.

Therefore, S2(g) would not have a heat of formation of 0 kJ/mol.