Max is exploring the properties of various compounds. Some of his explorations involve the use of a pH indicator that is red at low pH, yellow-green at neutral pH and blue to purple at high pH. He sets up several tubes containing water and the pH indicator and then begins to add some of the compounds (L, M, and N) he is characterizing in various combinations. His results are shown on the following table.

What can Max conclude about his compounds based on these results? Describe the likely events in terms of hydrogen and hydroxyl ions.