Apologia Chemistry Module 10: Experiment 10.2

I have had some time to think about Experiment 10.2.  A standard acid base titration is conducted in larger volumes, milliliters, not drops.  Usually, a titration is done with a buret and a lot of practice.  Burets, ring stands, and buret clamps are a big investment for one lab.  Larger scale titrations also require larger volumes of HCl and NaOH.  Microscale acid base titrations are cheaper and safer.  However, microscale volume drops are difficult to calibrate.  Scientists use micropipets not disposable pipets.

Yesterday, Lacie and I completed several different acid base titrations, including the ammonia-vinegar rough titration.  I did the Microscale Titration of Vinegar with NaOH and phenolphthalein (PHTH).  Dr. Wile does the titration in milliliters by measuring the difference with a graduated cylinder.  Microscale methods use drops for volume.  We did several trials for each microscale titration; however, it is difficult to calibrate the number of drops using a medicine dropper or a disposable pipette.  If you use the drop method, repeat the titration five times and average the number of drops to get to the endpoint.  Use the average number of drops to calculate the molarity.  DO NOT WORRY IF ALL OF THIS IS TOO FRUSTRATING AND YOU DECIDE TO JUST WATCH YESTERDAY'S VIDEO!  Under the circumstances, that decision is completely understandable.  Write the lab report and move on.

Here is the lab showing how to convert 5% acetic acid in vinegar into molarity.

Here is the video showing how to convert the molarity we estimated with ammonia and convert it to mass by percent.