Question

Which substance has Hf defined as 0 kj/mol? A.H2O (s) B.Ne (I) C. F2 (g) D.Co2 (g)

Answer 1

Answer: C.) F2 (g)

Step-by-step explanation:

Answer 2

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
`\Delta H_f`.

Every free element in its standard state has value of
`\Delta H_f = 0`.

Thus, from the given options only
`F_2(g)` is present in its standard state so,
`\Delta H_f` for
`F_2(g)` is 0.

Hence,
`F_2(g)` will have
`\Delta H_f = 0`.