Question

Why does the infinity reaction not require an infinite amount of time?

PROCEDURE:

1. Prepare 60 mL of a 1:1 (by volume) solution of distilled water and 2-propanol in a beaker. Be as precise as possible. After mixing well, wait 10-15 minutes to allow the contents to come to room temperature as some heat will evolve during the mixing of the two liquids.

2. Obtain ~20 mL of 0.05M NaOH and put it in a small plastic storage bottle. Set up a 10 mL buret, rinse the buret with a little of the NaOH solution and then fill the buret to the 0.00 mark with the NaOH solution.

3. In a 50.0 mL volumetric flask, weigh accurately a 0.500 g ± 0.020 g sample of tert-butyl chloride. Add the water:isopropanol solvent to the mark of the volumetric flask. Mix the contents well by inverting the flask several times. Record the time. This is the starting time for the reaction. Transfer the contents to a large plastic bottle and put the lid on.

4. The first sample should be taken out 5 minutes after the reaction is started. Subsequent samples should be withdrawn at about 10, 15, 20 and 30 minutes after the start of the reaction. For each sample, a 5 mL aliquot (portion) is drawn into a 5 mL volumetric pipet and transferred to a 50 mL Erlenmeyer flask containing about 5 mL of acetone (the quench). Record the time of the addition. Add three drops of indicator (bromothymol blue). The solution should be a faint yellow color. Titrate to a green end point that persists for about 10 seconds. If the color stays blue, you have added too much base. Record the volume of the base added.

   ** The first titration should only take about 0.5 - 2 mL of base. If your titration is out of

   this range, consult the instructor before proceeding.

5. To determine the infinity titer (when the reaction has gone to completion), a 5 mL sample

   from the solvolysis reaction is added (using the volumetric pipet) to 5 mL of water. This sample may be titrated after 40 minutes. You may perform this step at any point during the reaction, but sooner is better. Be sure to titrate the whole 10 mL mixture and DON’TQUENCH THIS SAMPLE with acetone.

Answer 1

Very good question.

Here you need to have some idea about reasonable approximation.