Acid/Base Titration Essay Example
Experiment 2 Acid/Base Titration
John J. Purdue CHM 321 – Fall 2012 TA: Scott Cole Section 1 September 4, 2012
Unknown Concentration: X.XX ± X.XX M (@95% confidence interval)
(adapted from a report prepared by N. Skrynnikov, 2009)
Abstract The concentration of an unknown acid (HA) solution was determined by titration with a standardized solution of sodium hydroxide. The standardization of NaOH was done by titration with a solid acid sample, potassium hydrogen phthalate (KHP), and phenolphthalein indicator. The unknown concentration (Cunknown) was determined to be X.XX ± X.XX M at a 95% confidence interval, and the methods described herein constitute a simple and reproducible technique that may be applied to quantitatively assess many different acid/base pairs, provided that an appropriate indicator is used to determine an endpoint. Introduction This laboratory exercise relies on a titration technique to determine an unknown concentration of monoprotic acid in solution. In the process of titration, a basic solution is gradually added to the acidic solution until complete neutralization is obtained. The ‘end point’ of the titration is detected with the help of an indicator as color of the solution changes upon neutralization. By measuring the volume of the titrant required to reach the ‘end point’, it is possible to relate the concentration of the acid to the concentration of the base. In this manner, the unknown concentration can be expressed through the known concentration. The concentration determination is repeated several times in order to improve the precision of the measurements and to estimate the experimental error. The experiment involves two steps: (i) Standardization of sodium hydroxide (NaOH) solution using potassium hydrogen phtalate (KHP) solution, and (ii) titration of an unknown monoprotic acid solution using the standardized NaOH solution. The two
John J. Purdue CHM 321 – Fall 2012 TA: Scott Cole Section 1 September 4, 2012
Unknown Concentration: X.XX ± X.XX M (@95% confidence interval)
(adapted from a report prepared by N. Skrynnikov, 2009)
Abstract The concentration of an unknown acid (HA) solution was determined by titration with a standardized solution of sodium hydroxide. The standardization of NaOH was done by titration with a solid acid sample, potassium hydrogen phthalate (KHP), and phenolphthalein indicator. The unknown concentration (Cunknown) was determined to be X.XX ± X.XX M at a 95% confidence interval, and the methods described herein constitute a simple and reproducible technique that may be applied to quantitatively assess many different acid/base pairs, provided that an appropriate indicator is used to determine an endpoint. Introduction This laboratory exercise relies on a titration technique to determine an unknown concentration of monoprotic acid in solution. In the process of titration, a basic solution is gradually added to the acidic solution until complete neutralization is obtained. The ‘end point’ of the titration is detected with the help of an indicator as color of the solution changes upon neutralization. By measuring the volume of the titrant required to reach the ‘end point’, it is possible to relate the concentration of the acid to the concentration of the base. In this manner, the unknown concentration can be expressed through the known concentration. The concentration determination is repeated several times in order to improve the precision of the measurements and to estimate the experimental error. The experiment involves two steps: (i) Standardization of sodium hydroxide (NaOH) solution using potassium hydrogen phtalate (KHP) solution, and (ii) titration of an unknown monoprotic acid solution using the standardized NaOH solution. The two