1. Increasing the molarity of the NaOH solution will decrease the number of drops required for the observed colour changes. It’s because the more concentrated a substance is, the less of the substance is needed to cause an equilibrium shift
2. When 6.0M NaHO was added to the iron (III) thiocyanate ion equilibrium system, the concentration of Fe3+ ion decreases. This cause the equilibrium system to shift left.
3. If the hydrated cobalt (II) ion complex was refrigerated, the temperature would decrease. This reaction is an endothermic reaction, so decreasing the temperature will cause the equilibrium shift to the left. When the reactants are favoured, the colour of the solution will get lighter to pink.
4. Equation: Co(H2O)62+(aq) + 2Cl-(aq) + energy ↔ Co(H2O)4Cl2(aq) + 2 H2O(l)
Energy is on the reaction side, so this is endothermic reaction. When we added heat into the solution, the solution changed colour from light red to purple. This showed that the equilibrium shifted to the right side. This is why energy is on the reactants side.
5. When NaCl is added to the hydrated cobalt (II) ion complex, the concentration of the chloride ion would increase, so the increasing concentration of the reactants would cause the equilibrium to shift right and turns purple.
6. Cr2O72- + 2OH- ↔ 2CrO42- + H2O
7. Adding a base NaOH will increase the concentration of OH- and cause the equilibrium to shift to left. The solution will become yellow, so K2CrO4 will stay yellow and K2Cr2O7 will turn yellow.
Adding an acid HCl will increase the concentration of H+ and cause the equilibrium to shift to the right. The solution will become orange, so K2CrO4 will turn orange and K2Cr2O7 will stay orange.
8. BaCr2O7 is soluble and BaCrO4 is insoluble
9. In step 7, there was HCL added to the addition of barium nitrate and this caused the reaction to shift right causing the production of additional dichromate. There for, there is no precipitate formed in step7 when Ba (NO3)2...