The equation with the concentrations of the products of a reaction raised to their stoichiometric coefficients divided by the concentrations of the reactants raised to their stoichiometric coefficients.

Explanation:

This is the description of the equilibrium constant equation. For example:

Given a generic reaction:

Where A.B,C and D are the reactants and products and a,b,c and d are their stoichiometric coefficients. The equilibrium constant of this reaction will be:

Note: is important to have in mind that the substances in solid or liquid (pure) state should not be included in the K equation.

imma come back to you hold on

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.