Question

At $298K$
${\Delta }_f{G}^{\ominus }element=0$
If true 1 else 0.

• A. 1

Answer 1

The correct option is A 1
Since no heat changes are involved in the formation of elements form themselves in their standard states, the standard enthalpy of formation of all elements is zero.
${\Delta }_f{H}_{standard}^{\ominus }element=0$
Entropy of every perfectly crystalline substance is zero at zero Kelvin. This is justified because , at absolute zero every substance is in state of lowest energy and position of every atom or molecule is defined in solid.
${\Delta }_f{S}^{\ominus }element=0$ at OK.
Also,
${\Delta }_f{G}^{\ominus }element=0$