What is in each test-tube? What proof do I have of this? Test-tube A: Test-tube A had water in it. I can base this on the fact that it was a neutral, reacting neither to red or blue litmus paper. Phenolphthalein also did not react to this substance. The pH value was 7, neutral, also adding to the proof that this substance was water, because water is neutral. The substance was clear and odorless, and all of these reactions combined led me to my conclusion of substance A being water. Test-tube B: Test-tube B had spoiled milk in it. The substance reacted to blue litmus paper, and red litmus paper underwent no change. Phenolphthalein did not change, and