how do i get the equilibrium expression for this formula?

Question

Ag2CrO4(s)-->reversible reaction<----2Ag^1+ + CrO4^2-

the products are both (aq) solutions

Answer 1

K = [Ag+]^2[CrO4(2-)]

Solids and liquids do not appear in the equilibrium expression. Only gases and species in solution.

Answer 2

the solid Ag2CrO4 should not be taken into account in the eqm. expression and thus the expression only takes into account the concentrations of only the substances in aq. states

thus it is = [Ag+]^2[CrO4 2-]

Answer 3

This is a Ksp expression.

Ksp = [Ag+]^2 * [CrO4--]

The activity of solids is, by convention, 1, so no need to put solid silver chromate in the denominator.

Answer 4

( [AG]^2 x [CrO4] )

Never include solids
Always include gases and aqueous
Never include liquids UNLESS every compound in the reaction is liquid (meaing homogenous)
If lets say both the products are liquid and the reactant is aqueous, you would not include the products since it's a heterogeneous mixture.