Determining the Acidity of Soda… An Acid Base Titration

Chemistry Name Experiment #20 Mods_____ Date_______ Determine the Acidity of Soda Partner

Objective To make a basic solution of NaOH To determine the molarity of 7-Up soda

Lab Safety (Skip 8 lines)

Prelab Calculations Calculate the amount (g) of NaOH to prepare 250.0mL of a .2M NaOH solution. Check your answers with your teacher before moving on to the next step!

Procedure, Part I Make your NaOH solution: Mass out approximately enough solid NaOH to prepare 250mL of a .2M NaOH solution. You may not be able to get your goal exactly due to the size of the solid NaOH pellets. Record your mass of NaOH. Carefully transfer the NaOH pellets to the 250mL volumetric flask. Add water to fill volumetric flask about ½ way. Use parafilm to seal the top and swirl to dissolve the NaOH pellets. Fill the volumetric flask to the appropriate line. Your NaOH solution is now ready to use.

Procedure, Part II Neutralization: Fill buret A with 7-Up soda (acid) and buret B with the base you made. Run 10.0 mL of 7-Up into the Erlenmeyer flask. Add 2 drops of phenolphthalein to the Erlenmeyer flask Swirl and add base to the flask until it turns bright pink. Add 7-Up until the flask turns clear. Add base SLOWLY until the flask turns the lightest pink Must stay light pink for 30 seconds Record the volume of 7-Up and base used. Dump out the contents of the Erlenmeyer flask and rink. Refill burets and complete lab again from step 1, but this time run 15 mL into flask

Data Mass of NaOH: _______g Trial 1 Volume of Base = _______mL Volume of Acid = _______mL Trial 2

Calculations Calculate Molarity of base: Molarity of Acid Trial 1: MAVA = MBVB Molarity of Acid Trial 2:

Calculations, con Average Trial 1 and Trial 2 Percent Error (MAactual = 0.001M; pH = 3)

Conclusion Titration involves the reaction between an acid and a base to form water and salt. We found the molarity of the acid to be ___________ and _______________ . My percent error was __________. Two sources of error include: