6. Rinse the graduated cylinder successively with tap water, deionized water, and 5.0 mL of 1 M NaOH solution. Measure 50 mL of the 1 M NaOH solution into the graduated cylinder. 7. With the temperature probe in the HCl solution and the plastic cover on the cup, begin measuring and recording the temperature of the HCl solution for at least one minute by touching the data collection button (triangle) on the lower left of the LabQuest screen. This will establish T i . Since the NaOH in the graduated cylinder has been sitting in the room for the same length of time as the HCl, we will assume its T i is the same.