29%(7)2 out of 7 people found this document helpful
This preview shows page 7 - 9 out of 12 pages.
22. Calculate the moles of sodium hydroxide (NaOH) used in each trial, and record the results in Data Table 1Moles= (Volume/1000) ∗Concentration23. Calculate the moles of sodium hydrogen carbonate (NaHCO3) used in each trial, and record the results in Data Table 1Moles NaHCO3= Molesacetic acid– Moles NaOH24. Calculate the neutralization capacity of each trial, and record it in Data Table 18. Gently swirl the cup for several minutes until all the pieces of the tablet are dissolved. The solution will have a milky appearance.9. After the tablet dissolves completely, place the cup on the sheet of white paper, and take a photograph of the solution.Note:If the solution is yellow after the tablet dissolves completely, insert “0 mL” in Data Table 2for “Volume of NaOH, total” and proceed to Step 18....ACTIVITY 2A Analysis of Tums® or Rolaids®1. Place the large plastic cup on the weigh balance and tare the balance. Carefully weigh 5 g of acetic acid into the cup. Record the exact mass of the acetic acid in the cup in Data Table 2 (page 11).2. Measure 20 mL of room temperature purified water in the 50-mL graduated cylinder.3. Add the 20 mL of purified water to the 5 g of acetic acid in the large cup. Gently swirl the cup to mix the solution.4. Add 5–6 drops of Bogen Universal Indicator to the solution. Gently swirl the cup to mix the solution.5. Place the cup on the sheet of whitepaper, and take a photograph of the initial color of the solution.6. Weigh one Tums®or Rolaids® tablet,and record the mass in Data Table 2.7. Break the weighed tablet into smaller pieces to help it dissolve, and add it to the solution in the cup.7continued on next page
10. Transfer approximately 10 mL of 1 M sodium hydroxide (NaOH) to the small medicine cup. This solution will be used to fill the syringe.11. Fill the 5-mL syringe with 1 M NaOH solution. Minimize the amount of air in the syringe by pointing the tip upward, gently tapping the syringe, and slowly depressing the plunger until the air is expelled. Be careful not to spill NaOH onto your hands or clothes during this procedure.12. Record the initial volume of 1 M NaOH in the syringe (to the nearest 0.1 mL) in Data Table 2.13. Add NaOH from the syringe in 0.1-mL increments. Gently swirl the cup between each addition. Continue adding 0.1-mL increments of 1 M NaOH until an orange color persists for a few seconds after the addition of the NaOH.14. Add 1 M NaOH dropwise from the syringe, with constant swirling, until a single drop of NaOH causes the solution to change to a yellow color that persists for a few seconds after the addition. This indicates that the endpoint of the titration has been reached and the solution is at the equivalence point.