Objective Acids, Bases and Indicators…oh my! Lab 13 Date: Acids, Bases and Indicators…oh my! Objective Observe a neutralization rxn & work with indicators. 250 mL of 0.10 M NaOH (1 gram of NaOH in 250 mL solution) 250 mL of 0.12 M HCl (2.5 mL of 12M HCl in 250 mL solution)

Experiment - Pipet 5.0 mL of NaOH into a clean Erlenmeyer. Litmus test on NaOH, record results in table Add 2 drops of phenolphthalein to the flask. record color change results in table Place about 5 mL of HCl into a grad. cyl. Litmus test on HCl Add 2 drops of phenolphthalein to grad. cyl. Slowly add HCl drops to the flask until a permanent color change occurs. Swirl the flask. Litmus test on neutralized solution.

Blue Litmus Color Result Red Litmus Color Result Indicator Results Solution Blue Litmus Color Result Red Litmus Color Result Phenolphthalein Color Result Identify as Acid, Base, or Neutral NaOH HCl “Neutralized” Solution

Analysis - Write a balanced chemical equation for the reaction in this lab; a salt and water were formed. Which solution (HCl or NaOH) was more concentrated in this lab? Explain how you know. What color is phenolphthalein indicator in a) acid, b) base, c) neutral solutions? When a drop of phenolphthalein is placed in a solution and the solution remains colorless, what can be correctly assumed about the solution? Why might the “neutralized” solution be acidic in this lab? Results -