Which of the following statements is correct

The addition of neon to a gas-phase reaction mixture at equilibrium at constant $$T$$ and constant $$V$$ does not alter the equilibrium.

For a reversible reaction in a closed system with constant $$T$$ and constant $$P$$, if $$\left(\frac{\partial G}{\partial \xi}\right)_{T,P}$$ > $$0$$ the reaction proceeds in the reverse direction, where $$\xi$$ is the extent of the reaction.

Complete dissociation of a weak electrolyte takes place in the limit of infinite dilution in aqueous solution.

The standard state of a species is always a pure substance.