4) Get a medium test tube and fill it with about 5 mL of water and a few drops of universal indicator. Take a soda straw and gently blow bubbles into the water. Note what happens to the color of the universal indicator What does the color of the universal indicator tell? Q. Balanced chemical equation: Solution 1. Answer a) Water turns to green when universal indicator is added to it as water is neutral. When soda straw is used to blow bubbles, As straw is basic it reactes with universal indicatoor to give greenish blue colour. b) Reaction involved can be : H 2 O + NaOH -------> Na - + H 3 O + .