CHEM 1031

1. CHEM 1031 Stoichiometric Ratio

2. Procedure PUT GOGGLES AND APRONS ON. Equipment Needed (per pair): • (2) 400 mL beakers • (2) 100 mL graduated cylinders • (1) desk thermometer • (1) stirring rod • (1) calorimeter cup (obtain from sideshelf)

3. Procedure (Continued) RECORD DATA IN INK, AND PUT NAME, PARTNER’S NAME, AND DATE ON FIRST DATA SHEET. • Obtain 350 mL of the 0.50 M NaOCl and 0.50 M Na2SO3 solutions in separate 400 mL beakers. OPEN AND CLOSE CARBOY VALVES VERY CAREFULLY. • “Guesstimate” 350 mL above the 325 mL mark.

5. Procedure (Continued) • Put thermometer in one of the beakers and measure and record temperature, estimating to the nearest 0.1oC. This is the initial temperature (same for all seven runs). • Set up ring stand, calorimeter cup, and thermometer thus:

7. Procedure (Continued) FOR EACH RUN: • Measure out prescribed volumes of NaOCl and Na2SO3 solutions using separate 100 mL graduated cylinders.

9. Procedure (Continued) • Combine solutions in calorimeter cup and stir with glass stirring rod.

11. Procedure (Continued) • Measure and record maximum temperature to the nearest 0.1oC. • Pour wastes down drain.

12. Procedure (Continued) • Rinse calorimeter cup with tap water and return to sideshelf when done.