Chemistry Honors – Classes 25 & 26

Dates

• Period B: Monday, March 2nd, Wednesday, March 4th
• Period D: Tuesday, March 3rd, Wednesday, March 4th
• Period G: Tuesday, March 3rd, Thursday, March 5th

Activity – Titration Lab

• Purpose: The purpose of the lab is to determine the concentration of a sulfuric acid solution by titration with a sodium hydroxide solution
• Background Theory: What is the balanced reaction? What is a titration curve? How is a titration curve used to determine the results of the lab? What are the basics of digital data collection?
• Materials: burets, unknown sulfuric acid solution, Erlenmeyer flasks, Distilled water, Standard hydroxide solution, pH probe, Magnetic stirbar, Stirring plate, beakers
• Safety: The solutions of H2SO4 and NaOH are fairly dilute, and not dangerous, but they are mild irritants. If spill them on yourself, rinse well with water. NaOH will cause a slippery “soapy” feeling; rinse until it is gone. Spills on benches, etc., should be cleaned up with paper towels. Waste solutions can be poured down the sink.

• Procedure: Set up the two burets, clamp, pH probe, and drop counter. The buret with the blue tape will be used for the base solution and the other buret will be used for the acid. Let each of the solutions run through the buret to ensure that the tip does not contain any air. Connect each probe to an airlink and set up the BlueTooth  of your iPad so that you receive signals from the two AirLinks. If your burets are empty, refill them with the appropriate solution. Record the initial volumes of both burets. Transfer approximately 5 mL (record exact volumes on the buret) of the sulfuric acid solution to one of the Erlenmeyer flasks and add about 50 mL of distilled water. Also place a magnetic stirrer inside the flask. Start the titration by starting the pH data collection using the SparkVue app and opening the valve of the buret containing the NaOH solution. Record the final volume in the buret. Record the number of drops corresponding to the final volume. Repeat this procedure twice. Dispose of the solutions dispensed during the titration. Make sure you save the file on your iPad
• Calculations: Be sure and do the proper calculations to determine the molarity of the acid solution.
• Analysis and Conclusion will be required for this lab.