Velocity of light in a medium depends on the of light and thus different colors travel with different velocity in a medium. Therefore, refractive index of a medium is of different colors. please give me answer fast please please please (fill in the blanks. )

The answer is c) pyrite

Answer is: the equilibrium  shifts toward the reactants, to the left side of chemical reaction.it is because lead(ii) nitrate dissociates in water: pb(no₃)₂ → pb²⁺(aq) + 2no₃⁻(aq).according to lechatelier's principle, the position of equilibrium moves to counteract thechange (more lead cations, common ion), the position of equilibrium will move so that the concentration ofproducts decrease and concentration of reactants of chemical reaction increase.read more on -