Solid copper (II) hydroxide from copper nitrate. First, add 30 mL of 3.0M sodium hydroxide to the solution in the Erlenmeyer Flask.Take a stirring rod and place the end about 1 cm into the solution; then tough the end to a 2 cm piece of red litmus paper. If the area of the paper where water is transferred from the rod to the paper turns blue, indicating excess hydroxide ions are present, the proceed with the next step. If not, add another 1 mL of sodium hydroxide solution and test again; repeat until the litmus paper turns blue.

In step two of Experiment 4, you add sodium hydroxide to copper(II) nitrate and use a stirring rod to test if the solution is basic. How do you establish whether the solution is basic? (Explain what else is needed, what observations are made, and what should be observed if the solution is basic).