This week we are going to investigate the movement of cations and anions through solutions.
Reading: The Home Scientist Lab Manual Topic II. Session II-2. Conductance of Ionic and Molecular Solutes, pp. 53-59.
Experimental Title: Lab 13: Conductance of Ionic and Molecular Solutes
Date of laboratory: August 26, 2014
Purpose: The purpose of this laboratory is to investigate the conductivity of distilled water, tap water, plus solutions of strong and weak acids, strong and weak bases, ionic salts and a molecular compound.
Read the background to the experiment on pp 53-55.
Briefly explain conductivity and resistivity. Write the equations for the reactions in your notebooks.
Special safety concerns for Lab 13:
- This week the most hazardous materials are the 6M ammonia, 6M acetic acid, 6M hydrochloric acid, and 6M sodium hydroxide. Please use gloves and goggles at all times when handling these materials. (MSDS for 6M Ammonia, MSDS for 6M Acetic Acid, MSDS for 6M Hydrochloric Acid, and MSDS for 6M sodium hydroxide.
- Remember to cover spills of acids with baking soda and spills of bases with vinegar.
- If a chemical spills on you, wash it off immediately. Be especially careful when handling the multimeter probes!
- Be sure to wash your hands very carefully when you are finished with this lab.
Materials: See list page 53.
I will do Part I (boiling the distilled water) for you before lab. You don’t need to write it in your notebook, but be aware why boiling of the distilled water was necessary.
Write down the procedures for Part II and Part III on pages 56-58 in the lab manual. Be sure to leave room for the data table to record your results. I will bring graph paper to graph your results, if you need it.
Template for the 24-well reaction plate:
Once you have completed the experiment and cleaned up, sit down and write a sentence or two to explain the results. It is always a good idea to do this part while the experiment is fresh in your mind.
Record any thoughts you have about the experiments, including:
- Possible improvements to the procedures or how to tweak techniques
- How the results differed from your expectations
- Whether the goals were met
- Suggestions for other experiments
- The answers to the review questions he provides on page 59.
Please leave a comment or send an e-mail if you have any questions before our meeting.