Neutralization titrations the determination of

I. Purpose: The goal of this kind of experiment is always to determine the weight % of Na2CO3 through the preparation of NaOH and HCl standards. The molarity with the standards will probably be found through titration of KHP for NaOH, HCl vs the known NaOH, and the unidentified Soda Lung burning ash sample compared to the well-known HCl.

2. Equations and Sample Computations:

Titration of HCl with NaOH:

Complete Formula:

HCl (aq) + NaOH (aq) ïƒ INGESTING WATER (l) + NaCl (aq)

Net Ionic Equation:

H+ & OH- ïƒ H2O(l)

Calculations (10mL zero. 1M HCL, 100mL H20, 7. 8mL NaOH):

# mols NaOH = zero. 1M (known concentration) back button 0. 0078L (titrated volume) = 0. 00078mol

one particular: 1 ratio mol NaOH to HCL = zero. 00078 mol HCl

Meters HCl= sama dengan 0. 078 M HCl

Standardization of NaOH vs KHP

Complete Formula:

NaOH + KHC8H4O4 KNaC8H4O4 + H2O

Net Ionic Equation:

OH- + HC8H4O4- C8H4O42- & H20

Measurements (0. 3291g KHP, 18mL NaOH):

# mols/M NaOH: = sama dengan 0. 089M NaOH

Dedication of the Unidentified Soda Ash Sample (Unknown # 67): Complete Equation: Na2CO3 (aq) + 2HCl ïƒ CARBON DIOXIDE (g) + H2O (l) + 2NaCl (aq)

Net Ionic Formula:

CO32- + 2H+ H2O & CO2

Computations (0. 1887g Soda Ash, reaction completed with 22. 80mL HCL total):

#mols HCL = 0. 0228L by 0. 078M (standardized HCL M) = 0. 00117mol #moles Na2CO3 = 2: 1 HCl: Na2CO3 = = zero. 00089 mol

Grams Na2CO3 sama dengan 0. 00089mol x 106. 0 g/mol = 0. 094g

% Na2CO3 by simply wt = X 95 = forty-nine. 94%

III. Data and Effects

Most titrations carried out with micropipette #8. All people found using balance #16.

Standardization of HCl with NaOH

10mL 0. 1M HCl diluted in 100mL H2O, Titrated with NaOH

Volume NaOH (mL)Description of Color at quantity added

Flask #17. 8Dark lilac, fast transform

Flask #27. 85Light pink, quickly change

Flask #37. 9Light green, slow alter

Mean Quantity NaOH: 7. 85 cubic centimeters

SECURE DIGITAL: 0. 05

RSD: 0. 64%

Standardization of zero. 1M NaOH

Quantity of KHP included with 100mL H20, Phenolphthalein signal then titrated with NaOH

Weight KHP (g)Volume NaOH

(mL)Molarity NaOH in titration

Flask #10. 3291180. 0895M

Flask #20. 207211. 20. 0893M

Flask #30. 246113. 40. 0894M

Suggest Molarity: 0. 0894 Meters

SD: 7. 071 x 10-5

RSD: 0. 07%

Determination with the Unknown (#67) Soda Lung burning ash Sample

Quantity of Soda Ash sample added to 50mL H20, Phenolphthalein indicator in that case titrated with HCl to the first equivalence point (Eq). Methyl Fruit indicator added for second Eq.

Pounds Soda Lung burning ash (g)Volume HCl (mL) Eq Point 1Volume HCl (mL) Eq Stage 2Total Quantity HCl (mL)% Na2CO3 in Soda Lung burning ash Sample Flask #10. 229914. 51428. 551. 24

Flask #20. 14218. 88. 7517. 651. 20

Flask #30. 188711. 511. 7522. 849. 94

Mean % Na2CO3 by fat: 50. 79%

SECURE DIGITAL: 0. 74%

RSD: 1 . 45%

IV. Conclusion

The standardization of the two HCl and NaOH produced Relative Standard Deviations of 0. 64% and 0. 07% correspondingly. Following the procedure for the dedication of the Soda Ash test utilizing these standards presented to an accurate and precise dimension of the Na2CO3 weight percentage. Given the info collected and calculations performed, unknown Soft drink Ash sample #67 is around 50. 79% Na2CO3 by weight which has a 95% confidence interval of fifty. 79% 1 . 66%.

This kind of value, however , has a distinct possibility of becoming incorrect or off goal due to mistake such as completely wrong calibration/use of the micropipettes intended for titration, both personal or perhaps environmental problem in the think about by difference method within the analytical balances, or the possibility of having trouble with differentiating the several equivalencepoints by simply color during titration. General, as long as there was no unexpected outside impact on on the treatment, the values determined are well within the 95% confidence interval and thus may be accepted.

1

Tweet