To set up the first equilibrium, place ~5 ml of water in a test tube add a couple drops of methyl violet indicator. record the initial color of the solution. choose a reagent that you believe will force the equilibrium towards the other side of the equation (cause the solution to change colors). available reagents will include hcl, hno3, hc2h3o2, naoh and nh3. add you selected reagent one drop at a time (with mixing) until a color change is observed. if your reagent does not cause the desired change, choose another reagent and repeat until the correct reagent is found. after you have changed the color of the solution, choose a reaction that you believe will reestablish the original color. add the selected reagent drop by drop (with mixing) until the desired change is achieved.