The solubility of iron(ii) hydroxide, fe(oh)2, is 1.43x10-3 gram per liter at 25oc. a. write a balanced equation for the solubility equilibrium

Fe(OH)₂ is solid which partially dissociates into its ions in water. It produces Fe²⁺ and OH⁻ ions by dissociation.

The equation for the reaction is;
     Fe(OH)₂(s) ⇄ Fe²⁺(aq) + OH⁻(aq)

to balance the equation, both side should have same number of atoms in each element.
Left hand side has 1 Fe, 2 O and 2 H atoms while right hand side has 1Fe, 1 O, 1H. hence the equation is unbalanced. to balance that, to the right hand side 2 should be added before the OH⁻ ion. Then the balanced equation is; 
 
Fe(OH)₂(s) ⇄ Fe²⁺(aq) + 2OH⁻(aq)