Essay about Irresistible Lab Report Chem 109

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A buffer is a solution that resists changes in pH when H+, OH-, or H20 is added. By using standard lab equipment, a lab pro diagnostic tool, and acidic and basic solutions, the pH can be found. By recording the pH while adding a base or an acid gradually to a buffer solution you can find the capacity of each buffer to resist drastic changes in pH. The best buffers will keep a solution from becoming either too acidic or basic with the addition of a strong base or acid.
The objective of the Irresistible lab is to determine the capacity of each solution (unbuffered and buffered both) and how much they resist changes to pH. This is accomplished by having ten graduated beakers: two containing pure water, two with .1 M
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In 2 and 7 I added 50 mL of .1 M NaCl. I added sodium acetate to the rest of the beakers: 1 gram to 3 and 8, 5 grams to 4 and 9, and 10 grams to 5 and 10. I then filled the beakers that contained the solid sodium acetate with 50 ml of .10 M acetic acid. Specifics can be found on page 84 of the lab manual. Though the lab manual instructed to use a pipet, we did not have an accurate 1 mL pipet or a graduated pipet, so we instead prepared two graduated burets with 1 M Sodium Hydroxide and 1 M hydrochloric acid. Using a standardized pH probe with a Lab Pro to measure changes in pH, we added 1 mL of HCl at a time and recorded the changes. The same was done for the NaOH.
We only added a small amount of HCl to the water and sodium chloride. We did not continue to add more HCl after a significant drop in pH was recorded. We added a total of 2 mL of HCl to both H20 and NaCl before the pH changed. The 1 gram solution of sodium acetate and acetic acid changed after a 8 mL, and the other two never dropped before we reached our total of 10 mL HCl.

The Effect of Acidon Solutions 50 ml H20 50 mL .1 M NaCl 1 g CH3COONa 5 g CH3COONa 10 g CH3COONa
Trial pH
0 7.51 6.37 4.74 5.57 5.97
1 1.59 1.38 4.54 5.45 5.88
2 1.12 1.18 4.37 5.35 5.75
3 4.18 5.24 5.68
4 3.98 5.15 5.59
5 3.76 5.07 5.51
6 3.45 5.01 5.46
7 2.98 4.93 5.41
8 1.63 4.86 5.34
9 4.81 5.31
10 4.77 5.26

We repeated the procedure

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