Which substance has hf defined as 0 kj/mol? a. h2o (s) b. ne (i) c. f2 (g) d. co2 (g)

The change in enthalpy when the constituent elements of a compound in their standard state i.e. pressure is 1 atm and temperature is 298 K forms one mole of compound in its normal state is known as heat of formation of compound.

The symbol for change in heat of formation is .

Every free element in its standard state has value of .

Thus, from the given options only is present in its standard state so, for is 0.

Hence, will have .

idk what the question is about