Methyl orange, HMO, is a common acid-base indicator. Insolution it ionizes according to the equation:

HMO↔ H++ MO-

red yellow

If methyl orange is added to distilled water, the solutionturns yellow. If a drop or two of 6 M HCL is added to theyellow solution, it turns red. If to that solution one adds afew drops of 6 M NaOH the color reverts to yellow.

a. Why does addinig 6M HCL to the yellow solution ofmethyl orange tend to cause the color to change to red? (Note thatin solution HCL exists as H+ and Cl-ions.)

b. Why does adding 6 M NaOH to the red solution tend tomake it turn back to yellow? (Note that in solution NaOHexists as Na+ and OH- ions. How doesincreasing [OH-] shift Reaction 3 in the discussionsection? (Reaction 3 isH2O↔ H++OH- ,Kc= [H+] [OH-] = 1x 10-14) How would the resulting change in[H+] affect the dissociation reaction of HMO?)